Because it is such a niche market we don't hear much from shuttle PCs. Most think the variety of hardware in shuttle form isn't anywhere near that of standard PCs, but the truth is there is a lot out there. Any media enthusiast knows the attraction of SFF, and sfftech has a review of a fairly powerful little box, the first Shuttle barebones Pentium M chassis, SD11G5. With a fairly pricey Pentium M and heavily integrated board combo, it comes with just about everything a shuttle PC needs with room for addition. It is fairly decked out with tons of outputs, and tons of features. It has an interesting heatpipe design for the CPU, which is fanless.
If you are interested in SFF you should take a look. It uses the time-tested G5 chassis, very popular among the SFF crowd with lots of visual appeal.