When Internet Explorer 7 Beta released to testers it left testers with a broken Windows Update that wouldn't load properly, disabling the ability to update Windows with critical patches that have been released since the end of July. This seems to of been fixed and on my PC it even redirects to Microsoft Update before my chosen homepage is loaded.
I'm not sure how long this has been fixed, because I've been away visiting family in England for the past 2 weeks. I checked my PC last night and wasn't prompted to use Windows Update (linked in IE7 Tools menu), but this morning I was redirected to Microsoft Update when I opened the browser.
It may not be the default action for everyone, but it seems now is the time to get those critical patches installed on your Windows XP box if you use the IE7 beta.
View: Microsoft Update