I've never been a silicone cover lover, but I do appreciate that some people like their shiny and unscuffed portable devices ... especially when many invest a lot of time and effort into a £500+ phone. I generally just try to take care of my phones and avoiding any case or cover.
I certainly think the iPhone 4 will outsell all previous models of the iPhone, but this signal issue is pretty serious if you ask me! I played with a demo iPhone 4 yesterday and the feel is top notch, finally no more cheap plastic and chrome. The phone feels B&O-like as a product, from its build material to its now sexy design. I agree it's a downer that the iPhone is such a popular phone, but when a phone gets this good, I don't really mind. The screen has to be seen to believed, I was amazed. I had read the human eye cannot make out any of the pixels and it's so true!