Hilva XNA Graphics Engine for XNA 4.0 CTP has released now.
Regarding the breaking changes in XNA 4.0 CTP and support for Windows Phone platform, Hilva has broken into several libraries to support all of the three platforms supported by XNA 4.0; Windows, Xbox 360 and Windows Phone.
In addition, Skinned model sample ported to the new version of the engine so it can run on Windows Phone Emulator. The updated sample can be downloaded from here.
The old sample is still available on the Tutorials page.
Please visit the Download page to get a copy of the engine.