Monster and Friends posted
a demo application for the iPhone that allows it to record video at up to 45 frames per second. In its current form, it can only record 5 seconds of video, but the developer expects the final version will record somewhere between 15-30+ fps and have an unlimited file length.
Gizmodo posts a video
demonstrating the application.
As always, this requires a hacked iPhone to install a 3rd party app, but does demonstrate that the iPhone is capable of video recording. Hopefully we'll see some official applications once the official developer's kit is release in February.