While the iPhone 4 was announced earlier today, that doesn't mean development has to stop on the iPhone 3GS. While we've seen this before, an iPhone running Android, it was never an iPhone 3GS and never Android 2.2.
It does appear that Android 2.2 runs on the device, but not very well. In the video, it is mentioned that the iPhone got very hot after five minutes of use and that Android will not recognize the phone's Wi-Fi card or GPU, but nothing major of course.
