I tried this app in the past. It was very....slow.

Which is why I think Apple rejected it. Their syncing protocol, even over USB, was painfully slow. Over wifi it was dreadful. Apple has a, "do it right or don't do it at all", philosophy.

They seemed to have fixed USB syncing in 4.3 because it takes me less time than before. I'm fairly confident that if he submitted his app after 4.3 was released it probably would have passed, but now that iOS 5 is on the horizon and contains the same functionality it has made his app irrelevant.