Nobody has tried it.
The parts fiche for the 2008 lists the Nav unit at $298 or so. I don't see a price (or part no) for the 2009 Nav on the fiche, but I would suspect it is about the same. You would also need the XM antenna. There is a XM button on the new audio unit as well, and I'm not sure if the meter panel from a 06-08 bike will work with the Nav unit. Then there is the issue of the wire harness changes and firmware for the new GPS.
I won't say it can't be done, but I also think it might involve more than just replacing the Nav board and getting a XM antenna.