Slipchuck I'm in the exact same position as you. I'm a proud K10 owner, that loved what the camera had to offer, but was frustrated by the slow auto focus and sub-par ISO performance. I too passed on the K7 because I felt that before I invested in pentax further (at this time only had a few consumer primes) I wanted to see them truly compete with cannon and Nikon in the performance category.
I have been absorbing as much information on the K5 as I possibly can (to the point that I'm starting to look like I have a k5 addiction problem) and I can honestly say it SOUNDS like its the real deal! The only issue that give me pause is the purple fringing problem. This is one of the quirks of the k10 that drove me insane, and I'm not excited to hear that the k5 may have the same ... issue.
For me I'm going to wait and see how the PF debate settles before I jump in and buy a K5, but either way I don't think you can go wrong with this camera
Here is a link discussing the purple fringing issue:
Field Review: The Pentax K-5 (Day 3) The Phoblographer
And there is a posting on this forum called:
"PF/CF evaluation..."