I don't know, I think I'd rather have a physical button that I can press with the hand I hold the phone with than have to do a four-figured operation on the screen.
I don't think the four-finger operations are on the iPhone/iPod, I think they're only on the iPad.
Correct. At least, that's the info that's currently available. :) If you try fitting 4/5 fingers on the phone, it's way too small to work well anyway. I don't expect them to show up there. If they do remove the button, I'd expect to see it only removed from the iPad.