Last week, ArenaNet announced guesting would be made available on January 28th. Guesting will enable players to play on a designated world pretty much like they were playing on their own server. You won’t be able to WvW, but you will be able to run around and party (The MMO kind, not the loud music and beer kind. Both are fun, though.) with other players.
The bad news is, with the introduction of guesting, free server transfers are ending on January 28th, too. So get in those transfers, now.
Get the details on guesting, here.