3. There will be no DRM.
4. You can read the spec here https://wiki.ubuntu.com/Specs/LucidUbuntuOneMusicStore
5. They are using an existing service (I dont think anyone thought it was going to be apple)
6. Because it will be connected to an existing service Major labels will be on board.
7. The store will more than likely only offer Mp3s but it depends on the partner who Canonical choose
the link you provide doesn't address any of these points