Microsoft have finally released IE10 for Windows 7. It seems their download page is getting pretty hammered. Looking at the requests on the page it seems that everything is held up with a request to ajax.microsoft.com. The page loads the template header, but no more. Surely in the day and age a company like Microsoft would load their ajax async and prevent a single script from taking down the page.
Update: it seems this is a problem with the latest build of Firefox's Aurora. Twitter is experiencing a similar problem with one of their scripts, so there may be a problem with Firefox's script engine.