Microsoft Operations Manager 2005 has just been released to manufacturing - the email went out 10 minutes ago. You can find out more about it right now at http://www.microsoft.com/mom/, or wait for the inevitable slew of marketing materials :-)
Update: the Microsoft.com operation tools team have been running a series of articles about their experiences with MOM 2000 and pre-RTM versions of MOM 2005. If you're worried about the upgrade scenario from 2000 to 2005, check out their opinion in "The only way to fly". Microsoft's IT staff have been deeply involved in the release process, and MOM 2005 is a better product for it.