Buy an album on iTunes and receive credit for already-purchased songs

The functionality isn't there yet but according to the article it could be at some point in the future. If so, this would be really cool. While this particular situation doesn't happen very often but there are times when I buy a single and then later want to get the whole album.

For example, I recently bought the "Lazy Eye" single by Silversun Pickups. The song is good enough to make me want to get the entire album but I'm going to have to re-buy that one song again.

Of course, this assumes you've bought the song from the "album" in iTunes and not a pre-album-release single which is essentially it's own one-track album. Unless they figure out some magic to give you credit for that too but I'm not hopeful.