Steve Jobs was like "one more thing, FaceTime, its revolutionary, its amazing, i can't believe its true, its not suppose to be laggy turn off your wi-fi people!!!!"Lol I am sure Apple will say the 4 doesn't have enough power to support FaceTime over 3g! Oh but wifi that works fine.
Typical Apple dropping features for no reason to seed new hardware sales.
The iPhone 4 has the same upload speed as the 4S and half the download speed at 7.2Mbps. Still faster than some WiFi access points. In these cases, the iPhone 4's faster cellular would give a better quality. I remember doing FaceTime over EDGE on my 3Gs. Quality wasn't the best, but it worked.Pretty sure it is called Facetime over Cellular and since the iPhone 4S has access to HSPA+ and "4G" networks, I can imagine that is why it is not available to the iPhone 4 since it does not and the experience would not be as good.