I just came across an interesting article how to use C# Async CTP about digging to internals and using some custom code to make t it applicable to Windows Phone 7 projects.
Check it out: Async CTP on WP7.
In case you haven’t played with C# Async CTP you probably should know this is next big thing in the world if multithreaded programming. Nowadays CPUs have more cores and by using I/O completion port and async programming model would make software solutions more scalable and threads will have less contention.
For more info check this PDC 10 video of Anders Hejlsberg