I might have to stick a rod through my head for using the term "game changer," but that aside, the front-facing camera on the new iPhone has significantly affected (not "impacted"...there, I avoided ONE cliche) my communications. This is one of several unanticipated changes from this phone. I was NINJA good at getting good self-shots from my old iPhone. I scoffed at the face-finding apps because I was waaaay better. Yet the front camera on this phone makes it crazy easier to take snapshots of yourself and someone else, which is really often the main content of snapshots. I mean, if you want a good picture, someone else is taking it.
More to the point, though, the ability to take video through it easily and without fear that you're filming somewhere near your right ear while you're talking allows the sending of...let's call them...video voice mails through MMS. Had someone described this to me a week ago, I would have found it tedious and unnecessarily pompous (same for Face Time, for that matter), but it's actually pretty cool and fun.
As for Face Time, I was SURE I would never use it, but I am actually using it quite a bit and like it. This from a chick who's video-chatted via Mac fewer than five times in my life. It's just cool. Perhaps the smallness of the screen ameliorates the "GOD THERE'S MY GIANT FACE" factor that pops up during a computer video chat.
And the "real" camera with the flash and everything allows me to totally dispense with my point-and-shoot (not my DSLR, obviously). I can't see any advantage to the poor old CoolPix anymore. If I want any higher-quality photos, I'll use the DSLR, and for video it spanks the Mino, much less my CoolPix video capabilities.
Take-home point: I like the two-camera system and the way the phone uses them.