I think people would be surprised at what you can do with how little if only they'd try. I've done real estate in some of the higher-end markets (a business that is close to non-existent right now!), and a perfectly acceptable cover came out of a 6mp file. Inside pictures were easily published from quite small copies of the files - "small" meaning quarter page. Why did I try? Because I had to: I didn't have anything else. Later I ended up trying 4mp for those sorts of work, and that is plenty also.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!