Mr. Pogue, over at the Times, has a great must-read on something photoheads have long known—when it comes to megapixels, bigger doesn’t matter (too much.)
The way I see it, people love simplicity, especially when shopping. If there’s any easy-to-read stat that registers as “more is good,” it makes it a lot easier for companies to push their products, and to force obsolesence (your 5-megapixel cam is worthless now that there’s an 8-megapixel out). I very rarely take pics with the maximum sharpness—they fill up your hard drive, look no better on a computer screen and I almost never print pics.
Breaking the Myth of Megapixels [NY Times]