TBH, the first thing I thought when I saw it was that it would make a great case for the video servers I'm going to have to build soon. You could put them in a bay and do all the administration from the front panel.
They do quite a few quiet boxes too, try their website:
Silverstone (the guys who make the case linked above) also make a completely passive design for mCubed. HFX. Check out http://www.hifiatx.com (which I believe I've also linked from another thread in the past).
It's expensive, but when you compare it to the price of a pre-built fan-less system it seems positively cheap.
Al the larger HTPC cases on that site are from Silverstone. The HFX case was about $500 US the last time I checked. That didn't include a power supply nor CPU heat-pipe.
You can check the prices yourself easily though. The HFX should be easier to get in Europe than it is here in Canada or in the US. What you install in the case is up to you - and that can go from simple to lavish.
