I just came back, some impressions, keep in mind I am not latest & greatest end game:
-New dungeons are pretty neat. Same stuff, decent challenges,etc.
-I can't even express the difference it made in my attitude and desire to play to be able to leave my chicken out while queuing for shit.
-Apparently using PoD for leveling other classes is way easier than any other method like fate/leve's. Especially since gear doesn't matter in PoD. I am still not quite sure why people run it. I think just XP and that i255 weapon, everything else is glamour or whatever
-WT(Wondrous Trials) are nice because every week you get a list of 16 random things to do, though you can only complete 9. Each one you complete you get a sticker that goes on to this bingo board type thing. If the stickers you get happen to make a line you can get some decent items/things as rewards. This alone is only a small perk, but what makes it nice is that it causes people to go back and do all sorts of older/strange dungeons that they normally wouldn't. So it's a good way to see things you may have missed or if you are new would otherwise never get to see.
-The PF(party Finder) being data center and not world is awesome. Always groups up there now for pretty much anything. I've formed groups for the most strange places and people will eventually join. There is also a little number next to a dungeon letting you know if there is a PF group up for that dungeon. Small but nice touch
As far as the classes/skills, seems like not much change yet, but I am not at the uber level of the game so I may not even notice. The big thing I would really like is for everything to be part of the Duty Finder window. Even PoD/Diadem/etc. As a new player it seems like there is too much to do and some things you have to go to a specific NPC to start it. When I first got back I had no idea where to go for this stuff, seems to make more sense to centralize it in an easy way for folks to find and participate, but that's just me.
I always thought the game was fun and that has not changed. Some major but simple quality of life improvements were made that made it more fun for me. There is still a fairly big wall with gear and mechanic memorization at the top most level, but that's currently like 3 zones/raids out of 100's so it's not a big deal. I'll always love the one character many class thing and think all games moving forward should do this. Also there can still be a ton of grinding for things like the epic, but considering you can get equal/better in just a few zones it seems like a moderate trade off for casuals.