4sysops has provided us with a pretty-close-to-really-official run-down of the up-coming Microsoft releases:

It is official now. Windows Server 2008 will be launched on February 27th. Joe Wilcox is speculating that the RTM might be available in November. If you didn’t start yet with exploring Microsoft’s new server OS it might be time to get started.

Vista SP1 will most likely be available around the same time. So you have about half a year left to learn about the countless changes in both operating systems relevant for corporate environments. And don’t forget that Office 2007 is also still in your pipeline, right? It seems this is going to be a busy summer. It will certainly take some time, until you will have fully mastered their new features and technologies. The earlier your start to learn, the earlier you will benefit from them.