The thermal reliability I've seen out of those Shuttle boxes hasn't made me eager to change my strategy of buying big-ass cases and putting big-ass power supplies in them.

How so? Out of the problems I have seen with Shuttles, only one has been thermal. My very first SS51 unit was one of the first 200 off the line, and they forgot some vent holes. With those missing, I was getting thermal lockups. The replacement however has worked fine, even running an ATI 9700 Pro, 2 hard drives, and a processor always pegged at 100%. The I.C.E. heatpipe on the CPU works very well, and the main system fan does a good job of pulling air in the front and side vent holes, over the components, and out the back.

Beyond my current SB51, I have friends with the SS51 (Radeon 9800 Pro), SB61G2 (Radeon 9600 Pro), and an SN85G4 (Radeon 9700 Pro). The problems here were the SS51 needing a motherboard replacement, after that friend removed a piece of RAM and put it back, not seeing a piece of conductive dust short out a few pins. The SB61G2 did suffer a power supply failure, about a week after he got it. The new one has run fine for months now.

I think the fact that Intel even has a "pico-BTX" motherboard layout suggestion now for the upcoming move to BTX means that mini systems will be around for a long time.