You are required to read this! I am a rabid foaming at the mouth GW fan and I will bite you!
There are huge differences between GW2 and GW. Characters can jump, swim, fight under water, and perform many other excellent feats besides! Entirely new combat system.
The entire skill system is different. Half your skill bar comes from what playable race you are. Multiple playable races with multiple classes, and the race bonuses include the unique race skills. It will play very different to be a Human or a Charr for instance. The other half of the bar is for your character class skills, warrior, elementalist, whatever. What class skills are up seems to be based on what weapon you are using or what you may have picked up.
http://www.guildwars2.com/en/the-game/combat/part-one/ Interim Report on GW2 weapons and combat.
http://www.guildwars2.com/en/the-game/combat/part-two/ Interim Report on GW2 weapons.
GW was a party game (players or heroes and henchmen); so a solo character in general got instantly crushed like a bug ... unless using a farming build which worked only in certain areas. This ... ummm ... sucked! GW2 has characters much more like WoW, they need no party in the explorable areas, they can fight on their own.
Or they can party up. Number of opponents and difficulty dynamically ramp up or down depending on the number of players in the party.
http://www.guildwars2.com/en/the-game/dynamic-events/dynamic-events-overview/ This is very worth reading. Not only will it be an open dynamic world, quests arise from dynamic events. They have completely rethought the quest system typically found in MMO. Each player's actions influence what is going on in the world. Sometimes dramatically! But this is not all. There will be a followup article on the personal story system.
"If our dynamic event system is putting the "MMO" back in "MMORPG," then Ree's article will show you how our personal story system is putting the "RPG" back in the "MMORPG." You won't want to miss it!"
http://www.youtube.com/watch?v=Ql41Y0n-sGc Elementalist Skills
http://www.guildwars2.com/en/ Official Web Site
http://www.guildwars2guru.com/ Primary English Fan Site
http://www.youtube.com/watch?v=Ph7FPTU_27E&NR=1 Playable Races Glimpse (omigawd!)
Release Date: Nothing official, but thought to be 2nd or 3rd quarter 2011.
Monthly Fee: $0.00. None. Zero. Zip. Free to play online forever. As with GW1, they will make money with expansion packs and bits and pieces from the company store. With the current GW, nothing in the company store is essential for game play. In five years, I have spent $27 in the company store for extra character slots.