Megapixels don't matter, at this point in a cell phone sensor more megapixels = more noise and worse pixels. People comparing megapixels in cell phones to megapixels in Nikon and Canon dSLRs are comparing matchbox cars to real cars. For most journalists and consumers it's just a big number they don't understand but they want it to be bigger because why not?
Larger pixels are better pixels. Pixels are like buckets, the more they can hold (what they're holding is electrons generated by photons) the better -- more dynamic range. The sensor in a dSLR is huge, if those pixels are buckets, cell phone pixels are like thimbles. Wanting more megapixels is wanting a smaller thimble. But it's worse than that, reading out a pixel creates a certain amount of noise, no matter how big or small the pixel is. If it's a small pixel that holds less, that means a very low signal to noise ratio, and overall more noise in the image the more of those pixels you have.
I'm a scientist who designs cameras for other scientists, and the main thing they ask for is bigger pixels. And more of them, so basically bigger cameras all the way around. (I can show you a great 111 Mpix sensor, but it's the size of a bathroom tile.) A cell phone is pretty much the opposite of all of that, consumers demand crappier cameras because they've been misled by journalists who have been misled by marketing types who won't listen to the engineers anymore. I used to go to an imaging conference (that's happening this week actually) where there were entire days of talks about cell phone sensors that boiled down to "how bad can the image get before the consumer will notice" and "what kind of processing can we do to the images so the consumers won't notice how crappy the image is getting as we add more megapixels?" But that conference got too depressing (and too irrelevant to building good cameras) so I don't go anymore.