Well it’s finally been released, SP1 for MOSS / Sharepoint 2007.
The best place to start is the technet resource centre.
Looks like there a few ‘gotchas’!
Watch out for the known issue of killing the registry settings for the foxit pdf ifilter if you are using that.
Looks like go slow, take care and test, test, test, for applying this SP.
Gavin's Sharepoint Blog 