It may just be a pipe dream, but there is speculation that Microsoft will announce a new version of Windows at CES, Windows Home Server. This would not be a full fledged new OS, but really more of a special purpose OS built on top of their current offering.
There is plenty of need for this as people are increasingly completely networked at home. As any business has found, this leads to the need to keep multiple computers updated and using a common security solution. They could also go the route of a proxy server to serve their home network. Maybe most importantly, they could use centralized storage to give everyone simple access to the same data.
There is also speculation that there will be some level of home automation built in. That would be nice. While there are already plenty of automation solutions out there, I think Microsoft could bring tighter integration and offer more features than we have seen previously.
I hope they do show it, there is a need for a home server type of solution. I imagine it will be a bit too dumbed down to be as useful as I would like, but it woul dbe better than nothing.