I guess it depends on what kind of publication. The stuff I have sold has been mainly in magazines or as ads for different things. The cover shot I had was a cropped image from a 5mp E-1. If they like the image enough, they will buy it.
Most of my stuff is not shot for commercial use. It is mainly for clients.
I shot raw and jpg today to see if there would be a difference. Which was really none. Though, I am *still* waiting for the raw files to process.
The majority of my PS work cannot be done in a raw converter, except for maybe lightroom. I may download another trial of that and see if I can use some cool presets and shorten my time in PS