I've noticed some weird display issues at both the WP support forums and in the codex (especially the edit boxes), even using IE 6.0.
I uninstalled 7.0b a couple of weeks ago, even though MS has really gone a long way to add complete support for w3c standards, etc. right now there are LOTS of quirks, I did a bunch of development for a client about a month ago and was using that as my browser, needless to say, the css was a mess in EVERY other browser, including IE 6, so until they get the rendering quirks resolved I wouldn't reccomend using IE 7.0 on your main machine, and only using it on a separate box and for testing only right now.
I really like it, especially the tabs, etc. but I'm not going near it 'till i'm sure standards support is working correctly.
As for the wp site and codex, I'm just using firefox right now, instead of dealing with the quirks in IE 6 i've been noticing.