I'm looking forward to my next PC build - an ION-based HTPC. I purchased from Amazon a ZOTEC ITX 330 ION motherboard with the dual-core Atom processor and an ITX case from AOpen. I plan to migrate my old HTPC in a much bigger Antec case into the small form-factor design.
A couple of issue remain - the AOpen case supports only one 2.5in hard drive and the old HTPC has a 3.5in HD. I'll have to buy a new notebook HD and migrate the OS. The other issue is that the AOpen case doesn't have space for an optical drive. Most of the ITX cases only support the slim optical drives. The existing HTPC uses a full sized dual HD format (BluRay and HD-DVD) from LG. The AOpen case offers a stacked option for a drive, but it's also for the slim drive and I can't find an online source that sells the stack anyway. So my option seems to be to use the optical drive in an external case. I' thinking using the XBox360 HD-DVD drive I have and replacing the drive with the dual-format drive. Not as elegant though.
I'll be posting pictures as the project gets going - hopefully this weekend.
On another note, I want to clarify my previous post. My posts on x86 and ARM are based on conversations I've had with former collegues from Microprocessor Report and are not based on any conversations at NVIDIA.