Yes, but I have seen (with proof) no reports of it causing any older gen iPhones to completely lose signal directly because of this reason. Sure, most phones suffer this to a certain extent, but with iPhone 4 the issue looks way more serious. On the surface it looks like a design flaw at the hardware level, so we'll see.
Some antenna guys have reared their heads to chime in having the antenna position there on the outside of the phone is dumb.
Some people have tried to blame the FCC, but Apple didn't have to have the antenna on the side on the outer edge of the phone right there. They could have put in completely on the bottom. And they could have tested the phone correctly and done something else. The FFC should have noticed it, but Apple should have had the engineering know how to realize it was a bad idea when it was on the drawing board. I'm personally steering clear of the iPhone 4 until I know more, and I'd most certainly recommend against given Apple any money for that device until they actually fix the fault. Steve is insulting right now, and he's not getting my money until they change their tune.