It was an interesting coincidence that F-Secure is commenting on the new Microsoft Update approach, as I used this approach for the 1st time on April 11th on some of my home and office PCs.  Microsoft Update is essentially Windows Update plus Office Update plus perhaps other products that might be found during the more comprehensive checking performed by this facility.  The Microsoft Update process worked well in my own testing of it and it applied all Windows and Office related updates properly.  As noted by F-Secure, you must be at least Office XP to use this facility.

F-Secure article: Forget about Windows update (use Microsoft update instead)
http://www.f-secure.com/weblog/archives/archive-042006.html#00000854

Microsoft Update Link
http://update.microsoft.com/microsoftupdate/