The Inq played around a bit with Internet Explorer 7 at CES 2006 and reports it looks and feels a lot like firefox.
The key thing is tab browsing that looks and feels like you are using Firefox. Even the search button at the left hand side looks and fells like this free browser. Just as in Firefox you can ad search engines.
There are some extra features as its easier to block the nasty sites and the RSS button is more accusable. Of course you can bookmark tabs as well.
The public beta of IE7 will come in the second quarter of this year.