I get the feeling that a large subset of the people bashing Program mode have never used it, and don't really know how it works.
I'm by no means a professional photographer, but I do think its important to know what all the modes on the camera can do!
On a Canon, Program mode can do everything (literally everything) that manual mode can.
In manual mode, you would meter, then the camera gives you a suggested aperature/speed based on the metering. Then you set those values. If you want a higher aperature, you dial that in, and at the same time reduce your shutter speed to maintain the same exposure right? In program mode, instead of having to dial in both the aperature and shutter, dialing up the aperature automatically dials down the shutter. So in essence, you can do the same thing, except faster!
Now, with manual you can over/underexpose. Lets say you have f4/60 and you want to overexpose by one stop (or 1/3 or whatever). You would open up the aperature, or increase the shutter time. Guess what? In program mode, you can do that too with the exposure compensation, which automatically will overexpose by 1/3 of a stop! You can still control whether it changes the aperature or shutters speed with 1 dial.
Manual does have some advantages. When you want to have consistent exposure for stiching panoramas, or you are in a studio with constant light settings, manual mode can save you time. Additionally, if you want to over/underexpose by more tan +/- 2 stops, you have to use manual because the EV compensation on your camera may not go that far.
Anyway, IMO neither mode is superior as far as the photos you are going to get. They both have the same capabilities. The only difference here is time. With P, you save time on varying lighting conditions. With Manual, you save time on unchanging lighting conditions. That's pretty much the main difference.
Just make sure you use/are familiar with something before bashing it =D I know Battou has already changed his statement to reflect this, and I respect that!
DATAstrm