Having had a bit of a think about this I've come to the conclusion that this issue really isn't that big of a deal.
Engadget, among others, have noted that the issue relating to sensitive areas on phones is well known and not limited to Apple devices. The thing is that this is the only device to have such clearly visible and easy to identify areas of sensitivity. Add to that the fact that no product by any other company comes under the kind of close scrutiny that Apple's iPhone does and you've got a big story out of what really isn't a big deal.
I can reproduce the issue on my iPhone 4 but I really have to try to make it happen. I don't see that as a problem. Under normal use I've not had an issue at all. Why would I worry about a theoretical problem that I can only reproduce on purpose?
It's understandable that people want their phone to be perfect in every way. I think Apple made a design choice here. They could get better reception with exposed antenna but that would mean a more obviouse area of sensitivity to reception degradation under specific circumstances. They made a call on that. You may not like their call or think they made the wrong one and that's why you can choose to purchase something else. In the end, it's only an issue if it's an issue and, for me, it isn't.
One of the few sensible posts I've read on the issue. You won't last long around here.