You have to love this alleged direct response from Steve Jobs:

C.K. Sample emailed Jobs earlier this afternoon about the issue. A few hours later, Jobs responded with the following:

Gripping any phone will result in some attenuation of its antenna performance, with certain places being worse than others depending on the placement of the antennas. This is a fact of life for every wireless phone. If you ever experience this on your iPhone 4, avoid gripping it in the lower left corner in a way that covers both sides of the black strip in the metal band, or simply use one of many available cases.

Ehhhhh....

Sure, the first part of this is true.  All cell phones have an antenna, and if you cover it with your body you'll attenuate the signal to some degree.  If the proximity or contact with your body causes the resonant frequency of the antenna to change that can also impact performance.

But it appears that Apple designed this phone so that you can effectively short the antenna out simply by holding the phone the "wrong" way (specifically, using the "wrong" hand!)

If true this is an amazing engineering screw-up, in that fixing it is basically impossible (without replacing all the impacted devices, of course.)

The iPhone has never been known for having "great" RF performance.  I have often wondered how much of the myriad complaints one hears about dropped calls and such are in fact device issues with the RF design rather than AT&T's problem.  One will probably never know for sure.

But this much I do know - the first and foremost design criteria for any handheld radio device is, of course, to be a radio.  That means that RF performance is paramount; all other considerations are secondary.

Nokia, for all its warts and issues over the years, has a well-earned reputation for RF performance in their cellular handsets.

HTC does a good job on balance as well.

If Apple blew this with the iPhone 4, they're in trouble.

Mark my words.