Adobe have published an update for Lightroom. The latest version is 2.1. They've added support for a number of recent cameras (such as the Sony A900) and fixed some bugs that I had not run into yet (so much the better).
Of course I immediately donwloaded it when LR 2.0 gave a pop-up telling about the update. All I can say until now is that 2.1 functions--and that is good news, I suppose!