ArenaNet will be at PAX East with a new Demo and a few amount of panels. PAX East will take place on March 11th in Boston and according to the blog entry it will be free to the public? Don't know if I read that part right so you may want to go to http://www.arena.net/blog/unleashed-at-pax-east-arenanet-travels-to-boston-with-new-demo to read more for yourself.
Sounds like a good time, wish I could go! I will be heading to Disney on that day though so I think I'll be ok!