From everything I read on GW2W today (http://gw2wiki.com/index.php/Main_Page), GW2 is supposed to be an expansion to GW, where all three chapters & GW:EN are all part of that world (and thus all available on the same game, tho Cantha and Elona may end up being unlockable because of the storyline).
I actually hope this isn't true. I don't mind the storyline continuing, but if you are able to use things in GW2 that you had in any of the toher games, I may not get it. I want it to be stand alone. The reason I don't play GW anymore is because of those add-on packs and GWEN. I didn't get them, and I felt left out / disadvantaged because of it. No way am I getting a game where you really need to have purchased four other things to take full advantage of it.