Gerbick

It doesn't surprise me that iPhone 4's antenna is more sensitive than iPhone 3Gs. Afterall, you are moving the antenna to the outer edge of the phone and away from all the inductive noise, which should improve the sensitivity of the antenna. So yes, it could have been great (and apple can probably still fix it in with some hardware mod in the next production batch, though they would probably need to compromise on aesthetics somewhat) had they thought about the minor issue of two antennas tuned to two different frequencies getting shorted by user's hand.