His article lists 5 reasons he's looking forward to developing UI's for the upcoming release. He also lists a few caveats to watch out for.
Me? I'm going to give it a whirl with somewhat low expectations. I moved away from IE back around IE5. I was a reluctant user when the first IE was distributed, but I must admit, IE 9 is probably going to be pretty good at release. My problem is, they usually fall behind the curve pretty darn fast.
If you're the technical sort, I recommend reading the comments listed below the story for some interesting feedback.
Hopefully Microsoft will decide they want a higher user market-share than simply what comes shipped with Windows Operating Systems.