HDMI output confirmed by David Airlie
Thanks and you are right :-)
In the meantime I watched the last minutes of David Airlie's talk (http://mirror.linux.org.au/linux.con...new_tricks.mp4)
At 37:10, a guy asks the 1 million dollar question:
guy: "With your latest work, does it mean that as long as I don't care about the fact that the Nvidia GPU doesn't ever turn off, you can actually display stuff through the hardwired HDMI port now?"
David Airlie: "Yeah, it would [... ??? ...] with all the updates installed it should work."
guy: "THANK you very much!"
Now, I hope Ubuntu 13.04 will bring all the good stuff to me. Or is this unrealistic for any reasons?