There is an article currently on digg where someone has conducted a test of AAC vs the Original. Actually I'm not even sure about that, it's unclear whether it's 128kbps AAC vs the original or 128k vs 256. Predictably the output is pretty much statistically invalid 50/50 either side over 4 songs..
http://digg.com/apple/Can_you_tell_128kbps...l_Take_the_test
I cringe when i read the comments...
