In order for a phone ( at todays current technology) to HANDLE 10 megapix, it is going to have to be a huge phone.
Since everyone is in a rush to buy the latest and smallest phone , this wont happen for a while.
Granted, you can put a 10mp camera in a phone. Sure.
But you wont see a diffrence between that picture and a 4 mp picture. Except that you will get alot of noise. ( Noise=misplaced color pixels)
It isnt the Megapixel that truly makes the picture look good. It is the camera behind the megapixels.
That is why, you get ho-hum, dusty looking pictures from smaller, high megapixel cameras . Those ones that are the size of credit cards?
Unless it is about a 4-5mp, dont bother. You are not going to get better photos from it.
I could go into the 'why' of how the camera applies when dealing with high megapixel pictures.. but. .I dont think that was the original question.

Im rambling..hehe