I was actually thinking the same, going for a Shuttle computer case, including motherboard.
I built my current computer in December of '04, and bought a Shuttle mobo+case.
Fantastic little creature - integrated sound (I don't need anything better), integrated wireless, tiny as hell, fun to look at; perfect for my needs.
If, however, you need an assload (read: more than one) of 5.25" slots, PCI slots (more than 1), etc, it's not for you.
The only two things that I *don't* like about it: I got a 220W power supply, and it's a non-standard size. I don't know if they make power supplies for my case that's over 220W. Secondly, it gets pretty damn hot when I'm running graphic-intense programs. I've had to take the case off on numerous occasions and stick it next to the window to cool it off.
Other than that, I love the thing. Very happy with my purchase.