Yes, and to take those lessons, especially from Solo classes--and disperse them among all classes. Give all classes "horizontal" tools that don't just add to their mob killing power, but affect the world and mobs in different ways. When you think about the "Solo" classes in EQ--they weren't powerful because they were the best DPS, or the most powerful classes. They could solo because they had the broadest amount of effects on mobs/the world. Roots, Snares, Mez, Fear, FD splits, pacify ect--these things are more than just CC, they are examples of affecting the mobs in ways outside of "reduce HP to zero".
If you want to create a modern game that draws in the Dark Souls crowd? Then you should design classes that play up things like that. Classes that are built for grouping BUT can take their tools and use them ininventiveways to overcome mobs with a VARIETY of strategies, not just one set one. And that's the main thing--giving playersfreedomwith their tools. And EQ did that. Yeah, a lot of boss mobs were immune to CC, but the most difficult part in EQ was oftengetting tothe boss mobs, not the bosses themselves. So you had these tools that worked on the most difficult parts of the game outside of huge raids (And even then, sometimes they worked--charming in the planes).
Now flip it to WoW--the most difficult aspects of WoW are the bosses themselves. So for a majority of fights, your "non-damage or healing or tanking" tools becomeuseless. You can't do anything to the boss, but what was specifically designed for in the encounter. Yeah, sometimes encounters are "designed" to let snares work, or whatever, but most of your tools are carefully controlled and only allowed to be used in a very careful plan. So your snare, roots, and a host of other controls essentially are a useful as a floppy dick on the hardest parts of the game.
EQ didn't work like that until much later in it's expansions. And it's that kind of freedom? That allowed for all kinds of interesting takes on how to do content. That, I think, is pretty amazing. And if you design a game around simpler scripting and more powerful mobs--and then give players a lot of tools, and let them figure out different strategies, I think your "world" will feel a lot more organic than if you simply give them one solution and a series of buttons to mash, in the precise order, to arrive at that solution.
I read this response a bit before bed last night and didn't get around to replying but it got me thinking on what REALLY is important in class design. Like what makes a game have OMFG THE BEST CLASSES EVER and maybe even have such an impact on people that in future games they STILL try out the class that has the most "spiritual" resemblance to their old favorite is their first pick? What makes this impression stick so hard that they are immediately disappointed by differences between this new character class and the one they loved?
I think this is to a large degree the result of classes having something "special" within the context of the game. This could be a matter of being the best at something, having a unique skill, or simply having such a cool combination of abilities that you felt like a badass.
Take EQ at launch:
Warrior - Best tank. That pesky ranger might be holding aggro 75% of the time but everyone in the group knew it was you who were supposed to be getting punched in the face. Crippling blows!
Cleric - Best healer. Also by far the single most desirable class in the game. People who hated you were nice to you usually because they knew someday they would need a rez. COMPLETE HEAL!!
Enchanter - Best crowd control. You could stack up so many mobs your group could skip out pulling for ages. Any shitty situation you rescued your group from made you a badass.
Monk - Best splitter/puller. There is no way your enchanter can handle that many mobs but that's cool. You just left half of them behind. Also awesome dps. Also flying kick!
Shaman - Best slow. Why bother with healing when you can just reduce the amount your group gets punched in the face. Also so many buffs. SO MANY. SoW? That's right. Level 9 druid bitch.
Necromancer - Best solo class. Yeah sure quad kiting swarm kiting blah blah blah. Exp soloing is meaningless in the end. You could solo shit that dropped shiny things.
Magician - Best pets. Yes, the tank is actually shedding real tears watching your earth pet laugh at the mob that was 3 seconds ago slipping a fist into the new asshole it had just created for him.
Wizard - Best BOOM. What was that? Starfire? Shock of WHAT? Lava Bolt lol like that's gonna land. Lemme show you how it's done... ICE COMET BITCH! Also, taxi hellooo.
Rogue - SURPRISE BACKSTAB - Sneaky, lock picking, corpse dragging, stab stab stabber. You sucked hard at release but you kept with it and now everyone loves you.
Bard - Rockstar. Only the spooniest need apply. WTF just ran by was that dude speed hacking? Completely unique abilities. Massive utility. Look like a giant blueberry.
Druid - Go to guy for SoW, Port, low level PL, sweet buffs, etc. Nothing they were best at but they had a little of everything and a lot of self sufficiency.
Shadowknight - Coolness factor? You probably win. Sure the warrior probably gets picked first to tank the raid. Not only do you have awesome utility but you can FD if you need to crap!
Paladin - White Knight, hero of the internets! - Okay maybe white knights got a bad rep these days. You could tank, you could offheal, you could even SOLO. GIANT FLAMING SWORD.
Ranger - The underdog. Staple class of all things fantasy. EQ implementation with hybrids being warrior + caster. Druid being already a hybrid you end up with a hybrid of a hybrid and well they weren't the hottest. Still fun! I played one to 50 on an emulated server and it was pretty damned fun. Probably most remembered as the WORST CLASS OMG by everyone who wasn't a ranger.
I know some of these things are seemingly reaching to make my point but honestly I will remember paladins with flaming swords, people hating rangers, druids being sow bitches, complete heal, lambent armored bards running fast as shit, etc etc til I die. Yeah if I think hard enough on it I can probably name off 2-3 abilities my WoW rogue had other than backstab. Which is funny considering that character probably has more days played than any two EQ characters I have. In the end though while WoW classes all have a semi-distinct flavor, maybe even moreso than most EQ classes (especially melee/hybrids) they have nothing that makes them stand out anymore.
Example:
WoW group - Oh man we need a heals! Okay, what should we get? WHO CARES EVERY HEALER ACCOMPLISHES THE EXACT SAME THING.
EQ group - Shit we need a CLERIC or this is going to suck hard.
WOW group - Okay guys I have a rogue, a mage, and a hunter asking to join... Which should we get? Well, the rogue can sap one mob out of the fight and do a lot of DPS... The mage can poly one mob out of the fight and do a lot of DPS... The hunter can trap one mob out of the fight and do a lot of DPS... Uhh.. who cares.
EQ group - Okay guys I have a rogue, a mage, and a ranger asking to join... Which should we get? Do we need a snare? Nope. Do we need any locks picked? Nope. Then get the mage duh!
WoW group - Should we get a puller? A what?
EQ group - Let's try to snag a monk to pull all of this shit.
WoW group - We need a tank. I guess any will do.
EQ group - We need a tank. Well try to find an SK so we have someone to snare, or a paladin for some backup heals, worst case scenario we can grab a warrior and I can root.
It's like even though a WoW DK and warrior and monk all play 10000000X more differently from each other than an EQ SK, warrior, and monk would the EQ classes still feel 100X more unique because they ARE more unique in their roles within the context of the game. All WoW classes have been homogenized to the point of being completely uninteresting in the name of balance. Screw balance. I'd rather play a character that is weak 85% of the time but within that remaining 15% I am a shining star of awesome. Who gives a shit if I suck compared to other classes in most things. I have my one special thing that sets me apart and makes me desirable.
My warrior may be a giant failure on his own. I may have a hard time running through even mid level zones without dying if I don't have another class's run speed buff. I probably can't solo shit that would move my exp bar even a pixel. Even if I could it would take me 17 years to regen the lost HP after. Pair me with a complete heal throwing cleric however and I am an immovable wall of awesomeness that my group can rally behind to defeat the forces of evil. And THAT is a cool feeling.