There are two issues at play with the iPhone 4 from what I've been able to gather.

There's the normal attenuation issue which can affect signal quality and then there's a software issue which is responsible for all the press we've been seeing. In other words, touching the antenna in a certain way "shouldn't" cause a complete failure of communication.

I think that's why we've seen the two distinctly different messages from Steve Jobs on the issue. The latest of which says there's no "reception issue" and to "stay tuned."