Last night a few guild members and myself took on Ragefire Chasm and the Wailing Caverns. While they're not the hottest dungeons in WoW they were a great way for us to all get together and start to see how we're going to work together as a group.
As guild leader it was a great way for me to see who prefers which types of roles so that I've got an idea of where we have gaps in play styles. At this point I'm pretty sure that we've got a member who'll work out as the tank. In the DPS department Azmim's re-roll as a Mage is working out for her so that's one.