Honestly, unless you don't have any room to fit a big computer, I don't see any point in making a mini-itx rig. It just limits your customization options and the amount of airflow you can have. Now that I have got that out of the way, I do think this is a really cool piece of technology. It seems everything is getting smaller these days, and maybe that is for the best. I just prefer to have a huge rig that both looks powerful and is powerful.
I'm building a M-ITX soon.
Awesome! Good luck with your build.
Steamboxes & media centers for your living room, lan-parties & conventions, minimalist offices, RV's (even pimped out cars/vans), live-in boats (like yachts/trawlers) to name a few reasons for mini-rig. I can see laptops overlapping some of this ground, but there are definitely solid applications for these boxes.