If you go to the Bing Webmaster Tools and login, then try to "add a site" to the list of sites you have rights to manage, you will get a page cannot be displayed type of page.
Here is a picture of the error I am seeing, as well as many other webmasters:
There are dozens of threads on this issue at the Bing Forums and will likely be dozens more soon. There is also a thread at WebmasterWorld with complaints.
Microsoft is aware of the issue and hope to get it resolved soon. I hope it is resolved by the time this post goes live, which is about 20 hours after the first report of it.
Forum discussion at WebmasterWorld and Bing Forums.
