The best thing to do is to hand over the domain to Microsoft. Just register a new domain name like Myfavoritemp3player.com. Ebay has done something similar to other folks. They've actually sued people. So just keep in mind for next time that you won't use other names in your domain name. The TOS's do explain this, but it's usually in legalese and not in plain english. Why companies do that? I have no idea. I often think that they like tripping people up. Microsoft is a big company and they have no problem wanting to by up Yahoo or Google, so it's better to just give up your domain name for another.