It blows my mind that Apple, of all companies, thinks that it is actually okay to delete all of a customer's data from their cloud storage service 'in order to serve you better', especially in a case like this where most of the files are probably music you bought from iTunes in the first place.
Apparently it's okay because it's still a 'beta', but this just seems lazy to me and may undermine any early adopters' faith in Apple's cloud services.