I voted for 5.5MP. These days, most of my work is for a newspaper, and for that, 2MP is sufficient for 99.9% of the photos. But I also like to print 8x10s for portfolios, gallery shows, etc. Most of the time, the 2.7MP of the D1H is enough and interpolates/sharpens nicely at this output size. Sometimes, I want a little extra resolution for fine-detailed subjects, cropping, and/or a larger print.
But I'm probably shooting 2.7MP files more than half the time. I also shoot a D1x, which is 5.5MP. On my D200, when I shoot jpeg for newsprint/online publishing, 5.5MP is my most commonly selected jpeg resolution. When I need a bigger file, I tend to go all the way and select raw on the D200. But for things like sports and regular PJ work, I can clear the buffer faster at 5.5MP, and waste less time processing, storage space, etc.
I do want to upgrade to a 12MP FX camera, but not for MP...for low-light image quality. Of course, I would also feel better shooting at 12MP in the future than my current 2.7MP and 5.5MP sizes.