12MP is the first digital resolution where I didn't feel restricted. Most of my prints are 13x19 so 12mp is enough.
"Enough" One beer is 'enough' too.
Will I take more? Oh, heck yes. Effective higher resolutions require more light to be effective. In full sunlight it would be awesome to get massive mega-pixels. The D800 is nice for group shots but more would be better.