From my understanding you can only use the Mobile 10 SDK with VS 2008 with SP1, not VS 2010.
I have both VS 2008 and VS 2010, I and I don't see any Mobile SDK in VS 2010, plus it has be documented that you should be using VS 2008 for Mobile 10 SDK.
I personally use VS 2008 SP1 for development of the mobile 10 application while my co-worker uses VS 2010 for a web mapping application.