1. Some of the zones have been revamped over the years and the geometry of this server has to match the geometry of live so there's a new Freeport, Oasis/South Ro, East Commons, Tox, Misty Thicket, etc. The only one of those that is really different is Freeport.
2. Paineel and The Hole are going to be there at release and they were later additions.
3. Exp is about double what it was during that time which is still much less than it is currently on Live. A level 1 killing a snake is like 5.5% exp before modifiers.
4. Speaking of modifiers there are no race exp penalties or class exp penalties but all exp bonuses remain. Human, halfling, rogues, and warriors I think all got bonuses?
5. This is an issue that died years ago but spells are more effective now than they were. If you compare dmg numbers, for example, you'll see basically everyone just nukes harder.
6. All classes that get spells now gain spells at a rate of one per level (and sometimes more) rather than the 1/4/8/12 or 1/5/9/14 progressions of old. Druids get SoW at 10 instead of 14, for example.
7. Shared banking is in. Maps are also in.
8. You can buy exp pots from the online store. Only the 25% bonus exp ones are available.
9. Summoned pets and Monk unarmed damage is very, very high in relation to what it was during Classic and it cannot be changed. At level 50 a Monk's fists have an attack/delay of 20/26 and Mage pets are going to make tanks irrelevant for a long time. The same is true for dps classes like the Rogue and the Ranger. They are going to be 100% outclassed by casters and Monks.
10. There are a few spells that were not in at release that will be present. Those mostly include Breeze and lower level rezzes for Clerics and I think Paladins. Nothing crazy.
11. If you die you'll respawn with all of your items. Corpse runs are not a thing.
12. There's a new looting system that is pretty good but if you don't like it you can just turn it off.