Let's see.
PvP is vastly different. There still is the old classic 8 on 8 GvG, also World PvP, where race, level, skills and all that don't matter.
You can bring a "companion" with you. They're similar to Heroes, but they don't take up a character slot in the Party Menu. If you don't bring them however, you get buffed instead.
And about the Level 100 cap, it still hasn't been undecided yet. It could go higher.
Movement has also been changed. No more "click to move". In fact, the controls are going to change a lot. You can interact with the environment, you can actually jump!
There will also be different "worlds". They're pretty much like servers on WoW. There's no limit to when and how many times you can change them.
If you were a player from GW1, you can attain extra items and stuff through the Hall of Monuments.
Phew, that pretty much sums up the info thats been released so far. Just tune in to the Guild Wars website, and you'll be up to date
