I signed up for iTunes cloud the other day and got the iOS5 GM installed on the phone. It matched 2000/7000 songs (not that great) and took about 24 hours to upload the rest. HOWEVER now that it's all set up... it's absolutely amazing. I have been LONGING for the day that I can get to my whole music library without having to worry about syncing/storage/etc. This is an amazing service... Makes 16gb of storage seem like more than enough.