Why?
Actually, why not?
In the Windows Server 2003 era, quite a few of us used it as a quasi-primary workstation operating system.
With Windows Server 2008 allowing you to define roles for it, I guess it was just a matter of time before it became the IT pro's workstation operating system.
In this post here, Steven Parker at Neowin has some insight, and a link to detailed installation/conversion instructions.
Really though, shouldn't you try it?