I'm looking to build the lowest priced and smallest home theater pc I can. There would be a chance, then, that if it was cheap enough and satisfactory, it may not be difficult to build/buy another. The goal is to get the lowest priced, smallest HTPC that can handle HD content for the future. I'm not sure yet about if it would need video in (TV, for example). I heard that MC may have a streaming TV feature over the network eventually and if this were the case, the tuner could be in the server and the HTPC could get TV from the network.
I've looked at Shuttle and found the $600 tiny one, but believe it or not, that still is a bit pricey. I may have to build it myself, which is fine. The overall goal is low price with HD content...hmm. Is it possible? I'd say DVI output and I'll use DVI -> HDMI converters where necessary.