Looking for camera with preview of shot before shot is taken?

I'm looking for camera with preview of the shot (with settings applied) before shot is taken, does anyone have any recommendations? I'm looking for something similar to the Nikon 1's Live Image Control. I want this feature because I like to take nightscapes, and I wish I could adjust the shutter speed and see the effects on the picture immediately without having to take a shot first. Also, I hope that the camera would have good low light performance.

As for size, preferably a light camera. Something about the size of the G1X/G12 or Nikon 1 Series. However, please let me know if there are DSLRs with this feature.

Added (1). Edit:
Thank you for your response!
@jimmymae2000: do you know of any camera that can preview such information before the shot is taken? I'm hoping that it will save me time when taking photos on vacation etc.

@Jens: Yea, its the overall brightness. I was hoping, since cameras can take burst shots at like 10fps or something, that maybe they could do a photo preview in the LCD screen? Its likely going to be a software solution though.

That's the beauty of digital photography, you get to review the results immediately and retake the bad shots. But for your application with low light photography i suggest a camera with an exposure histogram display may be very helpful. You can google "exposure histogram" for more info if you're not familiar with it.

" I wish I could adjust the shutter speed and see the effects on the picture immediately without having to take a shot first."

How is the camera supposed to predict that e.g. A car driving through the shot when you take a long exposure, and to show that car and its light trail on a preview before the shot actually was taken? What you're asking for is impossible.

Or is it the overall brightness that you want to be able to predict? If so, then any DSLR's light meter will give you a pretty good indication of the final brightness of the shot (albeit these are not perfectly accurate for long exposures)

There are settings on my Sony A57 which allow that. In A or S mode you can easily see the effect of +/- ev adjustment etc. In manual mode you have total control but what if the settings are very dark and you need to see?