I'm working on social software at the moment, and when I explain it to potential users, they seem to love the concept (which gives me confidence), but truthfully I don't know if will live up to expectations. I've found it best to downplay any potential success in my own mind so that I'm not disappointed if it doesn't take off. I hope your launch goes well; your comments are always insightful and glad to have someone of your experience around the traps.