Beo, my original post was mainly with regards to the new consumer cameras that offer 10mp+. It's all about the lens' resolving power and actual light control, for example flash control, something you can't really do much with simple point and shoot cameras.
Yes, mp does impact print sizes, but most people will rarely print beyond 10x10 inches and for that you don't need more than 6mp to start with. In those rare cases, Photoshop's interpolation can actually do a pretty good job.
For example, one of the more popular Nikon pro cameras is (still) the D2H (and the newer D2Hs). It's only 4.1mp! Yet coupled with a nice lens and in the hands of a pro, it can match virtually all current cameras in quality.
If you say you are seeing a fidelity changes between prints from different mp images then it's an issue with the camera's image processing than actual pixel dimensions, as actual image quality shouldn't be affected by the image resolution. I currently use a 6mp camera (to many people's surprise) and you will NOT see a difference in quality between 2, 4 and 6mp versions of an image if you view them at the same size (either resize to one resolution, or print to one final size).
Regarding Fuji: some of their cameras use a special sensor (I know the Pro S3, S5 cameras which use the SuperCCD sensor) that is basically 2 sensors in one. For example, the S5 has a "12mp" sensor, but in reality it's a 6mp camera. The advantage of the setup is that it produce images with a far better dynamic range (a really good thing), as half of the photo elements in the sensor are dedicated to the resolution, while the other half records extra image data. Some say that the S5 produces images that are closer to 8-10mp in actual apparent quality. It's a cool thing and so far, unique to Fuji.
Anyway, I don't want to burst anyone's bubble, but you will be hard pressed to get "amazing" photos from a point and shoot, in particular indoors. The cameras are just too limiting, in particular when it comes to light control (flash). Good photos are done by moving the flash OF the camera, or having multiple flashes working together to light the subject. You simply don't have that option with most consumer cameras...
If anyone is interested, I can post some sample pictures that will show how moving the flash of camera can have a dramatic effect on image quality.