Gavin Pugh released a new Amstrad CPC emulator which is entirely written in C# using Microsofts XNA library. This means that you can execute it on the Xbox360 and on your PC. With the development of this emulator he wanted to prove that it is possible to have a CPC emulator for that platform running in full speed, too. Don’t expect any progress on this emulator in the future, because he thinks, that the other emulators are doing a better emulation and his main goals of the project are met.
You can download the emulator and the source code from his homepage.

Here is a video, which shows XNACPC during emulation: