The HD capable ones were software mode (Eg, Twinhan) and not the more expensive hardware mode (Hauppahe Nexus-S) ones.
Now Bell HD is QPSK, so they used to work until the N2 switchover.
Dish uses 8PSK on their HD and only the new DVB-S2 cards coming out have 8PSK tuners. Hard to find, expensive and not well supported yet.
So the reality today is, nothing is working.
By the time we figure that out, dish will be MPEG4 anyway, so maybe need some new codecs to graph.
I agree it would be way cool if your sat provider made such a card.
Then the PVR would be a slam dunk and different apps could be run and you could choose your features and skins like FTA is now.
With cablecard and DCII being made external now, all the tech limitations are gone.