According to hardware.silicon.com, Microsoft revealed Longhorn Server (Windows Server 2007?) to 5000 people this week. Microsoft confirmed the release that these people will receive a beta for the next-generation OS. The Longhorn Server is not available for public download.
There is no date schedule for when a beta may or may not be made available to the general public.
As a recent certification graduate for Windows Server 2003, I am interested in the release, and would not mind having my hands on it. Windows Server 2003 (W2K3) features many new improvements from Windows 2000 Server, such as improved IIS tools, a poor-man's email server, more adjustments to the OS without requiring a restart of the server (this one is big!), and a host of other features. The OS has definately grown up since the days of NT!
I can only wonder what is going to be new for Longhorn -- perhaps more web extensions that work in a Microsoft-only world, such as IE things that only work with IE, and nothing else. Perhaps there will be other things rolled in -- unlimited terminal services, or licensing management tools. We should also see more support for 64-bit processors, along with more optimized code for the larger caches that are shipping today. Perhaps they will even optimize the libraries for the servers, so that the OS will adjust itself slightly depending upon the hardware platform.
While I can see why I still prefer Linux servers over the Microsoft ones (and I am looking at pure technology here -- not factoring in cost at all), Windows Server 2003 has shown me that Microsoft has a nice server product out there. I do have to wonder what Microsoft's vision of the future really is, and if I will be able to afford the hardware that the vision will demand.