Updates are always going to be complicated, even though the Automatic Updates utility is pretty good. So this explanation of how and where to get Office 2007 SP1 is quite useful.

Basically, this service pack is not going to be included in Automatic Updates for a little while. Not everyone wants to upgrade immediately, especially companies that need to check if their in house software still works or needs adjustment.

Office 2007 Service Pack 1 will appear in the Vista Windows Update page but will have to be explicitly selected for the time being. At some point it will be included in Automatic Updates but there's no word of exactly when.

It's always worth checking Windows Update though. I found a few updates for Office 2003 that we use here the other day that were quite old.