So I have a few machines that I keep on manual MUing so that I can wallow and experience patching with the masses (the regulated patches, etc etc).  So a machine I have was not offering up Vista sp2.  Nada.  Zilch.  Nothing.  So I asked and the brilliant Donna had the answer.  I was keeping myself from Vista sp2.  You see I had left the .NET 3.5 family patch that is rated "important" sitting there and had not installed it on this machine.  And when you manually MU, any patch that is important keeps Vista from offering up the pre-patch.

Once I hid the .net 3.5 family patches so that I had no more "Important" patches to install, then the KB 955430 was offered up. Once I installed that, then I got sp2 offered up.