You know all those IT guys who won't deploy a new technology until the first service pack is released? Well, it looks like the Microsoft marketing team has figured out a way to boost early deployments by skipping the RTM release entirely and going straight to Windows Server 2008 SP1.
I filed a bug report on this when RC1 was released. That was when Microsoft merged the Windows Server 2008 codebase with Windows Vista SP1. It's been that way in every build since then, including the latest pre-RTM build.
Bug or clever marketing scheme? You decide.