Hmm...I'll need to do more assessing but so far my members who are using IE7 says the site is displaying properly. So far we've only received a "DTD" error which is a different issue.
i've received no complaints from the IE7 contingent of users on my site. i use it myself and things seem to be working well so far. it IS only beta so for those having issues, i say hang in there. MS is definitely on the right track i think. we'll see if they do something with it or screw it up in the final release