Will iTunes come out with a Spotify / Xbox Music competitor?

This is really the only thing keeping me switching from windows phone to iphone. apple needs to release something similar to this to stay competitive IMO. and I know xbox music is coming to windows phone, but the best thing about xbox music is that you can download the songs while on wifi and listen to them on the go if you have a data cap like myself. have there been any rumours of this happening sometime in the future?