New York Times writer David Pogue has field tested and debunked the myth that higher mexapixel cameras take better pictures.
Pogue had a professional photo lab print out one photo (16" x 24") at 13, 8, and 5-megapixels. He then posted the photos side-by-side in Times Square and asked people to pick the "best looking" photos. Dozens of people gave up, saying there was no difference. Only one woman – a photography professor – was able to pick the highest resolution photo. (Pogue contends she may have been a lucky guesser).
In theory, you should be able to tell the higher resolution, but the reality is that it is very hard for humans to discerne a substantial difference at 5-megapixels or above, regardless of the photo subject.
So… for those of you who are looking for digitial cameras this year, just keep Pogue's test in mind. Hold off on the super-pixel cameras and just buy the 5-ish megapixel camera that meets your needs.