The ZMan:I've not heard much about that recently - do you mean the 'skymarket' rumours from last year? I've never seen any follow up on if, when and how this will happen.
Check the News wires today. Microsoft announced an "Apple like" store for their Mobile Phone OS allowing developers to sell applications and keep 70% of the profits. Basically its just like the XNA Marketplace for Community Games, Android, and the App Store. Even though it was just announced I was hoping to find a beta website or something like I've seen before.
Ballmer gave the announcement by the way and they are now known as "Windows Phones". :)