It is not available but it is certainly possible to develop it. I had it working once with a home made flight controller.
If it has to hover using height control and navigation, you will have to write more than just a little code; it will be a combination of features from ArduPlane and ArduCopter.
This does sound like an interesting project. I agree with Soren, most of the building blocks are there. You could probably do this in steps. i.e. develop code that would stabilize the plane after you've already done the transition from normal flight to hover as a 1st step. You could even elect not to control the throttle. The transition part is more difficult since you have to blend the flight control laws and gains into some sort of canned squence.
in 2014 theres still no option to hold a fixed wing plane in any orientation such as knife edge or 3D hover.
I'm guessing it'll be along soon now that Pixhawk is with us.
in the meantime, my solution is to fit an Eagletree Guardian in series with Pixhawk.
If I want to do aerobatics I select Manual on Pixhawk and activate 3D mode on Guardian - its fantastic!
if I find ive flown too far away, I select manual on the guardian and activate RTH on Pixhawk and she toddles home to Daddy
I know APM Copter supports conventional helicopters, but does it with a pixhawk enable them to do 3D aerobatics sequences like this: https://www.youtube.com/watch?v=ZefZcDDFyik
Has anyone done this?
Any work on this lately? Seems like it would be a relatively light and non-mechanically-complex alternative to tilt rotors and the like. Though... weight would be more limited, so maybe not a heavy duty uav, but I still like the idea.