Read this, which is an interview with some MS bigwig on win7 phone OS.
http://www.theregister.co.uk/2010/03...ils/page2.html

Read the second page.

Most notably these comments.
"That said, it seems there will be an exception. Kindel says that Microsoft is working with Adobe to bring the Flash runtime to Windows Phone 7, though it will not be ready "in this release," even though it is a native coded piece. I asked whether other runtimes such as Java might be supported? Kindel says it is unlikely."

And

"Which version of the .NET Framework is supported on Windows Phone 7? Kindel says it is a super-set of what Silverlight 3.0 provides, but does not include everything in Silverlight 4.0. He adds that although there are currently two distinct development platforms, Silverlight for general applications or XNA for games, Microsoft intends to bring them closer together in future."

So in the first release you don't get flash and the Silverlight you get ain't the version most people will be using.

Then reading further into the links, MS are splitting XNA for games and Silverlight for apps, with a view to merging later on, so the very future of silverlight is a bit shady.

This
"When building apps for Windows Phone 7, developers can choose between Silverlight, intended for general applications, or XNA, a .NET game development framework."

Is here.
http://www.theregister.co.uk/2010/03...ndows_phone_7/

So as a developer of apps for a win7 phone, what would you do? Learn one program language with bits removed - Silverlight, another XNA? To do a game and an app you need to learn both, which some might find easy, but most amateurs won't.

OR stuff it and do Apple and Android stuff.

The whole win7 interview is a list of things "not for this release."