As mentioned before, this is the camera I would use when I don't intend to do "serious" photography, I use the D3x otherwise either by itself or with a robust pano kit when I need serious resolution.
In this context, here is the value I see with the Nikon 1 series:
- the zoom lenses are smaller (18mm shorter for basic lens kit, 47mm shorter for tele zoom) and the system has the potential be become even smaller in the future,
- the AF seems much faster indeed,
- I'll be able to use my existing set of Nikon lenses if the need arises.
It will be interesting to see if the AF is significantly faster. They're marketing it as much faster, but this is one of the areas where the proof is in the using.
I'm personally not interested in using my DSLR lenses with these cameras.. if I was using a full size DSLR lens, considering it's size, I don't see an advantage to using it with a smaller body. Though, I am interested in "pocketable" lenses, those that are pancake in design or fold when not in use. I think this is what I like so much about the x100 over the NEX-5.. the x100 is what it is, you can't hang other lenses on it. So I use it in it's "pocketable" (true, large pockets) configuration.. and if I need more then I'll use a DSLR.
The E mount lenses do offer size advantages, but so far not enough to sway. If the Nikon 1 system's lenses are small enough, and I could carry several relatively small lenses in a situation where zoom makes more practical sense than a foot zoom.. then I see this as an advantage for the Nikon 1. But then so would a Superzoom. It will be interesting to see image quality trade-offs between the relatively inexpensive superzooms and the much more expensive Nikon 1.
The biggest question for me, is how much image quality I'm willing to give up and when, for the sake of small. Currently the Fuji x100 is my minimum standard for image quality, in that I'll use it with the expectation I can make captures I'll want to sell, print large, or use on my website without qualification. I've used 4/3's systems and I find they're on the other side of the line (if only just) for these purposes.
I love PNS cameras, my wife adopted our NEX-5.. but these are family function/outing image quality cameras. My wife is willing to carry the NEX-5 around for family functions, while I'm more happy with PNS style.. She says she likes the look of the Nikon 1 and would use it for family functions and light duty travel. But then she's Asian and fits the demo it's being marketed to..
You see, I think like many others here a modern high quality PNS is "good enough" for such functions. I'd like more image quality, but not enough to carry more size/weight in such circumstances. And for those special family functions such as graduations, weddings, etc.. I don't mind bringing along the DSLR.. in fact people count on it.
Will a 2.7x sensor camera's image quality make a difference to me? Probably not at current standards.
Sorry for being verbose.. but this is only part of what goes in inside my mind when deciding to buy a new camera.