We've released a few apps and found that the most successful were the ones which didn't fit any basic mold. At the same time, the more apps we make, the better we do.
andymoe's friend is the kind of story that Apple wants to have seen and they curate and control the medium to make it easier for people like that to succeed. I'm not saying they do the best job of it - crap copycat apps are in there too - but they have made a great medium for the persistent, innovative and determined developer to succeed.
Of course, when you make a medium that rewards persistence, unfortunately copycats can also succeed because they can be persisten too. Take the good with the bad.