Pretty much. Not necessarily always public games. I duo with a wizard quite frequently, and I have a friend that plays DH and Barb, and they bring some friends sometimes.
I rarely ever solo. I really hate soloing in Diablo games. Never did it in D2, either. Just boring stuff. That's why I can't get into Torchlight at all. No online.
Amen to that. Will be nice when they get around to doing something about the extremely anemic number of people in Inferno public games. Thats a huge reason why I dont find it fun playing anymore. Solo farming is fucking boring.