The guys in this videos have the smile of a cat who just ate the goldfish.
They are basically sneaking an ad-blocker into IE, under guise of privacy.
Just like AdBlock Plus, they don't take the responsibility of which urls get blocked, they let people publish filtersets (Subscriptions).
Ad blocking has not been a huge concern for the industry so far, because it is not that mainstream. But having it built into IE8 would make that possible.
Ad networks and web analytics providers are going to love this one.
This is not a new issue (
http://blog.monstuff.com/archives/000230.html), but it continues growing in momentum...