Adam Wilt got his hands on a prototype NXCAM "Prime" camera (NXCAM is the system name, the name of the actual model hasn't been revealed yet, so it was referred to as the "Prime"), and just posted his thoughts in a very extensive article.
The first part of the article is a thorough walk-around of the camera's controls, and the second part pretty exhaustively evaluates it's performance. He doesn't do strict comparison tests to other cameras, instead making general comments about how he feels the camera compares to cameras like the Z5U and EX1; this is a prototype, so that probably makes sense.
If you're thinking of getting one of these - or considering buying a Sony Z5U - you have to read this article, if only for the conclusion:
At NXCAM’s highest quality recording—1920x1080, 24 Mbit/sec AVCHD (MPEG-4) with uncompressed PCM audio—the Prime’s recorded clips clearly outclass the 1440x1080, 25 Mbit/sec HDV (MPEG-2) clips recorded by the HVR-Z5U.
Does this signal the end of HDV as a mainstream format? Quite possibly, even probably.
LOL! Notice at the end of the article his 16 CFR Part 255 Disclosure!!