Microsoft's problem is that the Android install base is 8x larger and iPhone is 5x larger (1)
I get that they're trying to create an incentive to developers but the reality in mobile is that if you have limited development resources, you develop for iPhone & Android.
The promise of a little extra revenue when you push past $25k feels more like a favor to their big platform devs than it does a compelling reason for smaller devs to look to the Windows platform.
What's interesting is that MSFT gets how to use killer apps to power a platform - remember when they just flat out BOUGHT Bungie to keep HALO an XBOX exclusive?
That move made the platform.
A touch evil and anti-competitive yes, but come on MSFT get more creative about solving this problem.
(1)http://www.comscore.com/Press_Events/Press_Releases/2011/11/...