The megapixel rating is actually important to different photographers in different ways. A portrait photographer with a 10 MP camera will be using 10,000,000 dots (pixels) to capture the face of a 5’5″ 102 lb girl. A landscape photographer will be using the same # of dots to capture a 4 mile wide valley with a 40 mile line of sight, with trees in it.

To the landscape photographer, the megapixel rating is important in the same way it is in satellite imagery: spatial resolution. Every pixel in every image represents area. On a portrait of a model, there are 10 million pixels covering a 2′x3′ area. On a landscape, there are 10 million pixels covering a 200 square mile area.

Sure, when it comes down to it, 10 million vs 20 million pixels may not seem to matter, but it doubles your spatial resolution. That’s pretty significant for landscape photog’s. So, if the pixel-quality of greater megapixel sensors could be the same as current lower-megapixel sensors, wouldn’t it be advantageous to go for the greater megapixel count, for archive and the potential for large-print use?

What matters most IMO, is composition, then light, then lens. MP is way down the list, unless you’re using an old Apple QuickTake, but even those could cough up a good image under the right circumstances.