I'm not too worried about reduced functionality in the short-term @btm -- anyone needing something we didn't take over can still use the Windows cookbook. MSFT views anything that's not an MSI as "bad", so in that sense if we focus on MSI for v1, we'll have handled the most important case. MSI can actually support idempotence. And then feedback can let us decide if it's worth it to take in the other stuff in future versions.  And testing the other types is not going to be fun -- we'll be able to get most customers in good shape if we focus on the most important scenario, ship it, and then add functionality as needed.

My only caveat to the advice I am giving -- RubyInstaller does not seem to use MSI packaging. :( So whatever format it uses (inno?) could be one of the first we do after MSI.