Scott Bourne over at Photofocus is currently (12 Feb 2012) running a poll asking how many megapixels is enough. This is being asked after the announcement of Nikon’s D800. Here’s the link if you want to vote: http://photofocus.com/2012/02/12/how-many-pixels-do-we-need/
I voted for 30+. In fact I’d go as far as to say the you can’t have enough megapixels (assuming quality remains high and you don’t go beyond what you lens can resolve). 100 megapixels, 1000 megapixels may wel come. I doubt they’ll be what is currently called full frame which after all is a strange measure because it refers to an old 35mm film standard. Chances they’ll be much larger than 35mm film and may get round the whole lens issue by having micro lenses embedded into the chips themselves. Perhaps not too, but I look forward to finding out!
So why do I want more megapixels? It’s quite simple. It gives you flexibility to recompose in post processing. I see a composition and take a picture. Quite often, when I have the photo in Lightroom or Photoshop I’ll see lots of options I didn’t notice at the time. The more megapixels I have the more options I have to realise those photos at an acceptable resolution.