Brian, I can't provide a definitive answer to this question but my guess is yes. Everything I've seen on the web indicates that the 6060 is a slightly decontented 6070. Most of their stats are identical, including their power ratings and THD, component video switching bandwidth, number of inputs, etc. They look the same (even the back panels are similar except for the 6070's additional features), they come with the same remote, etc.
I e-mailed Kenwood a week ago to see if the amps are the same and they haven't responded yet. My guess is that they are, in fact, based on the exact same design, with a few changes to the 6070 to comply with THX Select specifications and also to value-add some features such as the preouts, dual-zone capability, and optical digital out. It wouldn't make much sense for the 6060 to be a unique design using totally different parts.