Ars Technica posted a good article about why megapixels is hardly the de facto gauge of how good a camera is nowadays:
See, throwing more megapixels at the digital imaging problem is akin to bumping up the processor speed on a motherboard with a slow bus and small amounts of RAM, or adding a turbo to a small engine on a car with lousy brakes and wobbly suspension. The number of megapixels in a camera’s image sensor is just one in a number of aspects that truly define how well a camera works.
The short of it?
6MP is enough to make a very nice 8 x 10″ print—in fact, I’ve seen very nice, though soft, 8 x 10″ prints from early 3MP DSLRs.
Given that most cameras is well beyond 6MP nowadays, opt instead for other functions rather than buying in the myth of the megapixels. Of course, there are people who need more megapixels but do you?