[hmmmmm]

When I was on Drudge's site earlier this evening I was getting a continuous pop-up offering this "upgrade". I finally noticed that it's caused by a banner ad at the top of Drudge's page. It said something about mousing over this particular line of text to download. It looked exactly like something IE related. Needless to say, I was irritated enough by this that I won't be visiting the Drudge Report anytime soon.

[visualops]

The Google toolbar popup blocker is very effective. It's also easy enough to click the popup-blocker-button when at a particular website, to allow popups at that site only. For instance, for the message notifier here at FR.
As far as "upgrades", suffice it to say, don't download anything that you yourself didn't seek out at Windows Update.