Now they use a megaserver system, so all PvE is shared across different instances. So, although the instance you're put in automatically is decided by your server, you can join your friends in another instance easily. If you want to play WvW though, JQ #1 server. Albus and I are there, Skill is on Mag I think, and Talon is on the toast (TC).

Also, to add me on GW2. Account Name: Imprint.1597