Saxon 8.8. is coming out within a couple of weeks, and will have this capability (though it still needs some further testing). I suggest you wait till then. In principle you could get it working now by writing your code in Java and using the IKVMC technology to cross-call to .NET and COM, but it’s probably easier to wait.
(NOTE: If you follow the above thread, you will understand what this answer directly relates to, but in short, I’m “pretty sure” that the answer is a most resounding YES!!! :D)
Thanks Dr. Kay! This opens SO MANY DOORS for the .NET development world to begin integration of XSLT 2.0 into their existing and future application work flow. As such, my guess is that this new found functionality will have a HUGE impact in regards to the adoption of XSLT 2.0 on the .NET platform.