Some corrections:
A couple of errors in this story that should be pointed out:
1. When you buy music from the U1 store it is *automatically* synced to the cloud. That means that whilst 7Digital says there's a 3-download limit you needn't worry about it; the music will automatically be on all your U1-linked machines.
2. The choice of MP3 was not Canonical's; it was what 7Digital offered because it's what the record companies with whom they work offer.