I read carefully the last posts about IE8 new features on the IE blog. And the least I can say is that IE8 copies everything from Firefox... But warning, it smells like Firefox, but it's not Firefox. IE's extensibility is still zilch compared to Mozilla's, its security is still low compared to Mozilla's. Its speed is... well, read last Firefox 3.1 JavaScript announcements... Even on the innovative features, Microsoft is behind Mozilla : they invented the Activities and Webslices metaphors but almost nobody uses them ; in the same domain, Mozilla Labs' Ubiquity became in just one day the #1 keyword on twitter ! On CSS, WebKit is making giant progress on innovative stuff while Mozilla moves at the speed of light on already standardized features. Same thing for HTML 5 and other specs-to-be.

I guess BenB has an excellent summary about IE8:

<mconnor> is there anything IE8 didn't add?
<BenB> mconnor: about:mozilla ?