Here is a list of the Battlegroups.

http://wowwiki.wikia.com/wiki/Battlegroup

From what I understand you're now able to group for dungeons with anybody in your Battlegroup, its not just for PvP anymore. Just need to make note of everyones RealID.

My Guild is only for my boxing team, use the guild bank for everything for them. I am on Bleeding Hollow so wouldn't be able to group with you.