This phenomenon of people sending their home movies of iPhone 4 reception issues to impartial reporters Gizmodo reminds me more than anything of Uri Geller and spoon bending.
Geller, if you recall, used to make frequent TV appearances where he would empower people at home to bend cutlery using nothing more than their minds. Thousands of kids (of all ages) across the country would phone in, claiming that they too were able to bend a spoon with their minds, (when in practice, the application of manual force was the explanation that best matched Occam's razor).
While there may be a drop in reception in certain conditions: if you hold the phone in certain ways; if you have particularly sweaty palms; etc., I suspect that for most users, in most contexts, this is not a problem. And since, in sensitive reception areas, simply moving the phone as you pick it up can have an effect on signal strength, making an evidence video for Gizmodo needn't be much of a challenge.
But if there isn't a real problem, how do we account for the fact that so many people are sending in video evidence? Are they all crazy, like the physics-defying spoon benders?
Well consider this. In order to make one of these videos, you need to own an iPhone 4, and in order to be in possession of such a device this particular weekend, you need to have either found one "left behind" in a bar, or have been willing to stand in line for hours, just to be the first to own a phone that will be freely available in a few weeks time.
Draw your own conclusions.