Thanks for an interesting article. While I don't find flaw with your analysis, I think your conclusions are a little extreme.
I think the point ratio scheme is pushing at the edges of ethicality a bit (ie it's sleazy), but it's only one step down the road from pricing a $400 item at 399.99.
On the other hand I think the "interest-free loan" scheme is a pretty good idea. Microsoft can make a ton of money off the float from the spare points. How much interest can you make off of $4.99 (the max you'll ever have outstanding, regardless of what other comment posters here imply)?
This is one of the major ways almost every large company creates revenue. It permeates through all kinds of business to business transactions (although in that context it usually turns up in the reverse: payment is delayed rather than goods being delayed), and it's inevitable that it will hit consumers too.
Sure, a better company than Microsoft would use the interest they make on all that cash sitting around to lower prices for consumers. Maybe even Microsoft is. It's not clear if they're getting better or worse deals from the music peddlers than Apple is. I wouldn't be surprised if MS's margins are tighter.
I'm a big fan of the iPod and iTMS, and will probably never try out the Microsoft shtick, but I can't begrudge them making a buck (unless you count not using their stuff 'begrudging' ).
Zune Marketplace's Absurd Pricing Scheme