Yes, they do appear easily, specially if you have oily hands, but it haven't caused me many problem, I have get used to clean it with iKlear frequently.
But I don't regret buying the Black MB, and I don't think you'll regret it.
I have a black and a white macbook and black shows finger prints worse than white. White macbooks are a better value. Just upgrade the white macbook HDD yourself (easy project) and save the extra cash.
I don't have one but apparently what looks like "greasy" marks is actually the surface rubbing off. I'm not too pleased with that design choice, I have a 4-year old PowerBook that is virtually spotless in the trackpad area.
Very easy. You'll learn to live with it. The track pad and keys wearing seem more of a real issue with the blackbooks than fingerprints. Magic eraser works fine on prints but won't un-shiny your trackpad or keys.