Microsoft presumably want greater control over the service than they would have if they used UseNet.

By implementing their own NNTP server msnews.microsoft.com they are making access to it just a little bit harder than to any other newsgroup.
Also they are keeping out the alt.* flamers and insult-throwers because they would have to use _two_ newsgroups and that's technically beyond most of them I suspect.

They also have the ability to add login ID/password to provide private newsgroups under their control for beta testing, rather than still using CIS.

However, since the CIS forums are being KEPT OPEN by Compuserve (they want our money) and because Compuserve are offering FREE accounts to all Microsoft MVPs there may be little change in the forums - merely an "Under New Management" sign on the door :)

It will be interesting to see how Microsoft's new Internet Mail and News reader program progresses. I suspect they'll have a hard time competing with Forte's FreeAgent.
Also the movemenet of MVPs off Compuserve to the Internet sould be interesting to watch, if you're outside the USA then the Internet links to the USA are a bottleneck - since MSNews isn't replicated in Europe (and isn't likely to be) my access to is is appallingly slow even with Ethernet to me desk, let alone a 9600 Baud MSN link.

This might be a big NON-event <bg>