We came across the idea of developing a Hyper-V driver for libvirt during a project group at the university I’m currently studying. It was my part to evaluate the option of dealing with Hyper-V using libvirt as an abstraction layer. The project was finished in the end of 2009 with an internal prove of concept Hyper-V driver, which was just capable of doing very basic operations (such as power cycling, etc). That’s why the code was never released and after the project was finished, I stopped working on it, until now.
I know that there’s a potential demand for such a driver and it was (and still is) my aim, to bring that code to a quality, where it can be merge into libvirt. Unfortunately this task had a low priority after our project at the university was finished and therefore there was no progress, until now. Currently I am in stage of reorganising the (old) code and documentation, aiming to post it to the libvirt guys somewhere between october/november 2010.