Mike Garcen at MissingRemote just posted what looks like one of the most comprehensive looks at the history of Home Theater PCs that I've ever seen. Including screen-shots and a brief overview of all products.
The GeekTonic blog has been a little sparse the past two weeks as my time has been stretched so thin I barely have time to even read let alone write about the content you come here for, but this is a must-read for anyone even slightly interested in HTPC's.