Word is that Microsoft is going to be disabling the DRM servers used to authorize music purchased from the now defunct MSN music store after August 31st of this year. If you were stupid enough to buy music from Microsoft's store then you won't be able to activate the music if you move it to new computers or upgrade your operating system, so, if you've haven't moved to vista and you want to keep your music playable you'd better hurry, otherwise you'll either have to buy a new computer or lose all those tunes you thought you were buying, when in fact you were just renting.
The bizarre thing is, I don't really understand why Microsoft feels it has to shut these machines down, I mean it can't take a huge amount of horsepower to keep these old servers working, and Microsoft is hardly lacking in resources. There's probably some upgrade policy which is forcing the migration of hardware to new revisions of windows which just don't support the old DRM servers, and there's nobody working on keeping this old software up to date. There's probably some scary security holes in the old DRM server software which have never been patched and it's easier for Microsoft to betray those trusting pioneers who bought music from them 5 years ago, than it is to ask a few interns to keep the servers up to date.