Microsoft! Live.com is totally broken in IE8. Which I find kind of odd, because I would have imagined that the Live.com team had access to the beta. At any rate, changing tabs doesn't work, the Start Orb is broken, and only 3 of the panels on my front page load data.
Oops! I think we can say that this not the first site that will break with IE8, and definitely not the last. Time to update that meta tag, guys!
This site, however, is totally ready. One change to the global configuration in IIS7, and we're now spewing the IE7 compatibility HttpHeader, although there are relatively few issues with the way the site renders by default in IE8.