This is more of a note for myself, but I thought I'd share it with everyone.  I just watched the Channel9 interview with the WIX team and it looks VERY interesting.  I've been looking for a better way to build installs since I HATE INSTALLSHIELD!  I've used the setup and deployment projects in VisualStudio for some simpler projects but found it to lack extensibility.  WIX, according to the team, is used by virually all the Microsoft products.  I will have to check it out when I have time.