I don't like the auto updater in the security centre for 2 or 3 reasons:
It's slow, it slows down the computer while it's doing it's thing, and it sometimes fails to install 1 or more updates.
It installs willy nilly (when it's working) whatever MS have decided is good for you, without giving you the choice.
If you aren't on a fast connection, your downloads/page loading etc slow to a crawl while it's doing its thing, without you always knowing why.
Try setting the security centre to "notify me but don't download or install them"
When, at that time of the month, the yellow shield pops up, do as batninth suggests, go to MS update in IE7, and view the available downloads to choose. The amount of research/deciding is then entirely up to you .
I would suggest NOT installing the WGA notify tool.
Right clicking on the yellow shield allows you to select from a menu tab an option that basically says "don't notify me of this update again" which is worthwhile. Having done that, on the update site, you will see a message "you've chosen to hide important updates...blah blah blah", which should cause a warm, feelgood glow of satisfaction.
'Tis all about control.