This is the (only) good news. Less problems for those developers that fight everyday with N different stores (read: policies) in order to bring their programs to embedded devices.
This is going to solve a HUGE fragmentation issue from an app store perspective. Also, this should simultaneously provide a far great user experience.
I think Microsoft has a winner as far as their mobile OS is concerned, now they just need to work their asses off and deliver the next point release update before August.
That and also make sure they do everything in their power to make the development process uber smooth.