Its up to the vendor, but I would suspect that the soldered down HDMI output would take priority and the audio from the GPU would be routed to that (in otherwords audio would not be routed to the DVI as there is no need for an HDMI adapter in this case).
One of those three outputs would also have to be running in clone mode with another as well.
After a good night of sleep, I can explain myself a bit better again, and what you said last is exactly what I meant; the chips have 2 transmitters for DVI(/HDMI) and 1 output for TV-Out, right? So to have 1x HDMI + 1x DVI + 1x VGA, one would need to be running in clone mode, or the VGA would have to somehow be eating the TV-Outs signal, which I don't think it can?