looks shit, runs like a snail compared to other browsers I've used, you can't mod it and for me as a firefoxer it doesn't have adblock plus. But I don't think slicker was eww at the fact it's IE the idea of a browser on a console is what he dislikes. Its pointless and makes no real sense.
IE 9 is great, I've switched back to IE from Firefox. Anyway thought MS were always against putting a browser on the Xbox. I think its worth doing but lets hope its better than the browser on the Wii or PS3
The reason why Phlash and Cow (and almost every other web designer for that matter) hate IE so much is because it doesn't conform to the various standards set out by the W3 council, the body behind web standards like HTML and CSS.
It often means they have to code one version of the website for Safari/Firefox/Chrome/Opera etc, knowing it will work almost 99% as it should, then hack the fuck out of it to make it work with IE.