The Inquirer explains how bad NVIDIA is behind in HDMI:
BACK AT CEBIT, we asked Nvidia about its HDMI card, or cards. The press chap informed us that there is such a card, manufactured by Nvidia for Sony for its OEM system. That was the only one and it still is the only one, as far as we know.
Nvidia played the old game of blaming the manufacturers and said that none of its manufacturers wanted to produce an HDMI card but we think it has something to do with the software support as well.