[Edited link]
At long last Microsoft officially announced today (20-Feb-2008) the Windows Essential Server Solutions, which includes Windows Small Business Server 2008 (for up to 50 users), and Windows Essential Business Server 2008 (for up to 250 users).
Err… http://www.microsodt.com/essential is not actually the correct link! 🙂
Thanks, Will. If these fat fingers keep getting in the way, I really need to switch to voice/speech technology!