Interesting: I started with 5,677 songs in my library and now have 5,813 and counting up as it goes (taking a long time to upload stuff, I guess ;-) ... it appears to be adding 256 kbps versions of purchased songs to my library if the ones I had were at the old 128 kbps rate and flagging the old ones as duplicates. Since it's still grinding away, I don't know if it will eventually replace the 128 ones or just keep them flagged when all is said and done =)