My good friend Iain explains why there won't be a Service Pack 1 for Windows Server 2008:

I had a bunch of people internally ask me why Windows Server shows it's version as Windows Server 2008 SP1 (for brevity - WS08).

The history here goes back to problems we had form the split we had when we broke Windows XP from Windows Server 2003 (WS03) way back in 2000.

The first Service Pack for WS08 will be called SP2.

A fascinating story.