ws08 server backup is the same as the vista business/ultimate/enterprise version.
Install the Windows Server backup options.
Backs up to VHD format. Almost capable of doing bare-metal restores.
Minasi: http://www.minasi.com/newsletters/nws0801.htm has a nice readout of using it with Vista.
I just duplicated that effort with a smallish WS08 installation....very nice.