Just saw this on Engadget!
The traditional p&s line of cameras posses a basic drawback in the form of slow focus and shutter lag. For many home uses, and consumer uses, this is a real problem as you are forced to pose people to snap a good shot. Pictures of anything moving like a small child, or a school dance, are very hard to achieve.
The real improvement in the new(olympus, panasonic, etc.) smaller bodies (MFT etc.) is that this hurdle seems to have been overcome. Technology now allows a fast focusing/shooting NON DSLR body. This is a major improvement and opens up a world to consumer use.
Nikon made a smart business move, to develop a small sensor body, with fast focus and speed. As sensor technology improves - the physical size of the sensor is less meaningful, allowing nikon to provide smaller better quality lenses, and keep costs down. I believe most consumers are not seeking interchangeable lens systems, and do not want to lug around a MFT body and lens. Nikon gives us a smallish body, with super fast performance.
I think this is a very smart business move.