Sylphan

Seeds of Destruction comes out in October, that's less than ten weeks away.

There will be some significant changes to the group window, especially because of mercenaries. This info comes from Fan Faire, not from beta.

I'm afraid they might do it similar to the inventory window, and hard-code most of it so we can't modify it much. But in case they don't, here's what's coming:

The group window will show the mana and endurance bars for everyone in the group, as well as health bars!
Mercenaries will have their name show as a different color than real players in the group window.
The group leader will be able to specify who is the main tank, the puller, and the main assist -- and a little visual indicator will show next to that person's name in the group window.