its all just smoke and mirrors on Apple's part. 2 tests of actual dB change make it clear: If you picked up an iPhone 3GS and held it normally you might get a less than 2 dB signal drop or about 2/3rds the unheld signal strength. Pick up an iPhone 4 and hold it normally and you get an 18+ dB drop or about 1/80th (!) the unheld signal strength.
This is a design flaw and all the dancing around won't change that. Fortunately just about any kind of cover will fix this. Finally got to see the Apple bumpers - massively ugly, so got the Ghost Armor. With it I no longer drop calls at home so that solves my problem though I still hope Apple gets run through the legal wringer over this.
(as an aside that's why the idea that corporations are people is ridiculous, the 'right thing' for a corporation is to do whatever makes the most money, the 'right thing' for a person to do is admit their errors and behave ethically.)
My bumper arrives tomorrow so I will see. My friend got his last week and he said that it only helps the issue, not solve it. Fingers crossed I guess.