i think you miss his point, its not the point of how easy it may be to convert but why have to do it in the first place when mp3 where already supported. like previous poster said it should be a choice to have either not just one. The psp for that matter handles mp3, atrac, and acc. the wii could have used this option as well.
my question why change it in the firstplace when you could have just implemented a music channel. it seem a lot of fuss to change something thats not that big a deal any way.