Name server problems? or did Microsoft forget to pay their bill again?

It seems like a number of Microsoft related web sites have vanished. www.msnbc.com www.microsoft.com I've tried from both AT&T and Earthlink, and can't reach them. The name servers don't seem to be returning valid answers. If they are in your cache, it works. But after clearing the cache, nada. I noticed name server problems earlier this evening. Is this spreading?