I just found a very promising digital audio workstation for Linux. Wired is beta quality, but the screenshots look great. It is a KDE app, much like Rosegarden, so that makes me happy.

I think that with the right hardware, Linux+Wired+Rosegarden could make a very happy studio. Now, if only they had Reason for Linux. (Yes, I do own a copy of 3.0, and yes , it works on both Windows and Mac OS X).