Thanks to Blog reader "eddie", we have the following YouTube Full HD sample video clips recorded with the K-5 and the D7000:-
K-5: http://www.youtube.com/watch?v=s3n4qqh7M2s (162 seconds, 149.796 MB)
(Remark: I don't believe that this video is "official", contrary to its given title. If it really is, I think the staff who made it should be fired!)
D7000: http://www.youtube.com/watch?v=60-xwkYsKd0 (92 seconds, 46.319 MB)
This is what eddie suggested, quoted: "I just checked out some D7000 testvids from YouTube downloaded with Firefox YT downloader addon. The video is suprisingly good! From the pentax K-5 i could only find one featuring a horse in a rather "squary" rendering. More testvids of the Pentax k-5 please! (before i sell all my Pentax stuff and get a Nikon)"
I have downloaded both video clips and viewed them on a Full HD 1920 x 1080 monitor. I've played back the video with a Quicktime movie player on a Core 2 Duo 2.83G PC machine w/ a GeForce 9800 GPU, which I think this combination is far more than enough for a super smooth playback with the highest possible video rendition quality.
I do agree with eddie that the video quality of the K-5 clip is inferior, as it is obviously more blocky and the playback is not as smooth as well.
As for the video file efficiency, both video clips are in 1080p, the K-5 file is 0.925 MB per second, whereas the D7000 file is 0.503 MB per second. So, the K-5's memory requirement is almost doubled (even putting aside the difference in video quality) and it loses again in this match! :-(
Anyway, do wait for more sample videos from different "comparable" cameras including the D7000, A55 and also the A33 or even the NEXes, which share the same or closely designed Sony sensor(s) of the same latest generation. Time will tell..