These comments have spoken about the "MS currency" aspect of this system.
What about what that means to an individual using it? The only legal complaints you may be able to make, or issues that may be resolved as a consumer are with the "money for points" exchange. Any other issues you have, like with what you get for "spending" points, could be up to MS alone, in their newly created economy. You may be very limited with what you may do regarding what you consider "value" for a points exchange since it is not a "real money for product" exchange.
They are separating the music from the purchase! Spending points can be interpreted as "signing their one-way agreements" as far as their new "economy" is concerned, leaving you without much of a legal recourse. (virtual money and virtual objects that go missing or taken away in an online game come to mind)
This sounds like they may be able to use this licensed/non-purchase-purchase as a selling point to any music labels from whom they seek music-product. After all, in their system, they can play prosecutor/judge/jury with any issues the users bring up in regards to the "non-sale-sale". Potentially also giving more weight to their own or their suppliers desires regarding use of their "non-sold-sold" products.
Or is this all in my head....
Zune Marketplace's Absurd Pricing Scheme