I forgot to mention a couple of things about the NEX cameras in the entries below. First, I think the cameras only make sense when used with a small lens, because the whole idea behind the NEX system is small size. When you put a big lens on a tiny camera, the package is still big, sorta like using a Sony 300/2.8 with an small A290 or A55 body, because you don’t want the full frame camera bulk. The little extra weight and size won’t be noticeable because the lens is such a dominating factor. The current 18-55mm kit zoom lens puts the NEX cameras at the very upper end of practicality.
Another idea might be for Sony to offer some Carl Zeiss prime lenses scaled down specifically for the NEX system, and possibly with the intent of trying to capture some of the Leica mystique. There are adapters out now for Leica lenses, but in my opinion, most people will want AF capabilities, and that unfortunately will hinder use with current Sony a-mount lenses, and to a lesser extent all other non-NEX (e-mount) lenses. I’m guessing the average NEX user won’t pay $2000 for a Leica prime lens with no AF, and the snobbish Leica user will never allow his lenses to touch a Sony camera!