I personally would love it if FaceTime came to Mac and PC platforms. As of today, I don't have many friends that have iPhone 4's so I hardly ever use FaceTime.
But in the near future, I would be able to video chat with my friends that have the 4th Generation iPod Touch and anyone who has a Mac or PC.
This wouldn't just be an Apple service anymore. Anyone would be able to do PC-PC video chats with this new technology.
I can't wait for this to become popular, then this will finally solve our problems with other video chat clients.
I would be starting to use video chat on regular basis. Can't wait!