I am looking forward to their next album too! I think with this one they wanted to try something different and new and see where it took them and some of it was perfectly executed while other things were a little less fine tuned. It's easy to assume that it was Joe's direction that they were going in but really I felt as though it was more influenced by Ryan and Brian and what they like and what they are interested in sounding like. I expect that the next album will be when they've honed in on what they want. Although, we can always blame Brian for not using the hand drums as much. ;)
I'm super excited to meet people that even know who Guster is, so yay! Oh and Joe is totally an awesome guy, you should check out his solo album or his stuff with his band Joe, Marc's Brother.