The development story for Windows Phone 7 has been revealed. As suspected, it is heavily based on Silverlight, XNA, and Flash. So much in fact that only managed code is allowed on the platform.
With ever more sophisticated attacks against native code appearing ever year, it isn’t surprising that Microsoft is locking down Windows Mobile 7. The new platform will only support managed applications that can be sandboxed, such as those created with Sivlerlight, XNA, and, according to Tim Anderson, Flash. While Flash is a nod to consumer demand, and perhaps a way to one-up Apple, Sivlerlight and XNA are the real stars in their mind.
Underneath everything Windows Mobile is still using the.NET Compact Framework. This supports core services such as LINQ, isolated storage, and Windows Communication Foundation. On top of that is the common services such as sensors, networking, media, and sound.
From here developers have to make a hard decision. An application can use either Silverlight or XNA, but not both. Aside from the features pushed down into the common services layer like the aforementioned XNA Sound and Media libraries, the two cannot be mixed.
Update: An earlier version called the product "Windows Mobile 7". The official name is "Windows Phone 7".