Here is a quick test of the video recording and editing capabilities on the iPhone 4. This video was shot in low light while the iPhone was held stationary with an In Your Face viewbase. I used iMovie for the iPhone to edit down several different takes into one 30 second spot–then I exported and uploaded to YouTube–all from the phone.
The process was relatively simple with the biggest hitch being the amount of time it took to trim the video clip. You highlight and drag, recenter, highlight and drag. It was the only part of the entire test that wasn't a breeze.
The IYF viewbase is still available through amazon for $29.95. My only note would be that it makes a better holder for watching videos than it does for shooting them. There are probably better solutions out there, but I had it handy and it worked in a pinch.