The Eye of the North expansion pack is set for a holiday 2007 release, and will cost less than the previous chapter additions. It features no new professions, but will include new armor sets, new skills, new heroes and new areas to explore. Its storyline will bridge the gap between the first game and Guild Wars 2.
Guild Wars 2 meanwhile, will feature four new races, and "radical" changes to many game elements including PvP play and the NPC companion system. It also sounds like there will be less instancing, and the level cap will be either really high or non-existant. The game will also remain fee-less. A beta is expected to start in 2008. For much more, go here.