The inestimably erudite Mike Walsh has provided a detailed breakdown of the fixes in the MOSS 2007 Service Pack here: http://wss.asaris.de/sites/walsh/Lists/WSSv3%20FAQ/DispForm.aspx?ID=1298

And, after you have spent time with your loved ones and enjoyed some festive cheer, read Joel's "12 days of SharePoint Christmas" here: http://blogs.msdn.com/joelo/archive/2007/12/17/12-things-to-do-over-the-holidays.aspx

They could be made into a song to the tune of the 12 days of Christmas :-)

"On the 12th day of Christmas, Joel Oleson blogged to me,
Recover your content,
Download training vids,
Update quota templates,
Review management tools,
Subscribe to RSS,
Tweak Content DBs,
Attend a conference,
Reseeeearch 64 biiiittt,
Read up on MOM,
Plan perf mon,
then some cap plan,
And prepare for Service Pack 1"!

Merry Christmas!