MSN Music purchases not compatible with Zune

lewiz writes: "The BBC are reporting that music purchased at MSN Music will not play on the new Zune music player. From the article: 'If they start buying from Zune, they will need to get to get a new Zune device, and their existing music won't go with them.'
I personally find this very surprising and a little worrying. What would happen if Apple tried this?"