So, thus far this what I found (prices are estimates or MSRPs that I could find) and some of the information is courtesy of Grassroots Motorsports Mag:
Contour+ ($500):
Self contained camera, provides 1080p (30 fps), 960p (30 fps), 720p (60 fps). Full HD and HDMI compliant, has GPS module, so you can map the video onto Google Maps, water resistant and comes with three mounts and up to 32 GB SD and external hi-fid microphone. I think this may be one of the best choices.
http://contour.com/camera/contour_plus
Datatoys ($300):
rugged and lightweight, WDR-600 bullet camera, which is really a Sony CCD, vibration resistant. 1080p at 60 fps and includes GPS and accelerometers with data overlay with video. Can also overlay 3D image on Google Maps, has a 3.5" touch-screen LCD, but I think this all is in the upgraded version, not the base unit. Some links on their web site does not quite work, so hard to view the comparative data.
http://www.datatoys.com/consumer.php
GoPro HD ($300):
I think we all know this one, but it is good to keep it in the list. 960p @ 30 fps, 720p @ 60 fps. The interesting part is a 3D version is coming up. Basically you connect two GoProHDs with a specific length 3D bridge together and the bridge integrates the two videos to form a 3D version of the capture. Now, this should be beyond interesting to watch. But the price doubles of course, but nonetheless it should be very interesting to watch. I wonder if data overlay software would have a problem with it, but it should be very interesting watch. Have I said how interesting it would be to watch???
RaceOptics Evo HD ($450):
The camera head features a 5 mega pixel HD image sensor housed in a waterproof aluminum casing keeping it safe from the elements. The camera utilizes a 150 degree field of view at 1080p and 480i and 170 degree field of view at 720p allowing a clean wide angle but not distorting the picture.
Built-in microphone has specific wind noise reduction, also has a external mic jack, and comes with wireless remote and 4 GB SD.
http://raceoptics.com/evohd7.html
You may also want to check out:
ReplayXD ($190): replayxd.com
Swann SportCam ($99): swannsecurity.com
Hope this helps.