Excellent question. To my knowledge there are no stereo audiophile HDMI equipped DACs. I would not expect that to change for the following reasons.
1. HDMI is a closed standard as opposed to an open interface standard like S/PDIF & AES/EBU. As explained here:
http://www.hdmi.org/manufacturer/adopter_registration.aspxthe first step in designing a HDMI equipped device is to sign the non-disclosure agreement and send the keeper of the standard a check for $10,000 (or $5,000 +$1/unit shipped) then you can start designing. For companies like Sony or Denon who are used to sending $250,000 checks to dolby Labs and dts to buy into those standards the $10k for HDMI must seem down in the noise. For the small and medium sized companies in the audiophile niche its serious coin.
2. Once the hardware layer of HDMI is accessed the hirez audio data we are after is wrapped in encryption called High-bandwidth Digital Content Protection (HDCP). See:
http://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_ProtectionBefore one gets the decryption keys another annual license fee is paid this time to Digital Content Protection, LLC, a subsidiary of Intel. While forking over more dollars one is signing more contracts basically promising the device you put the HDMI hardware and HDCP software on will not be used as a means to hack the content for unauthorized use and if it is your company is responsible for damages. And this is backed up by the Digital Millennium Copyright Act (DMCA) so if there should be a problem it is not at all unlikely you will be discussing it with federal agents from the Copyright Office. Admittedly much more likely is the other SNAFU the HDCP brings to the party, HDMI handshake issues. As part of HDCP security scheme source and playback devices exchange identity and characteristics and the data is formatted or even shut off in response. The handshaking between devices' hardware and software is notorious for breaking the link in customers' homes.
3. Once the dollars and legal aspects are dealt with the technical side is not so rosy. Plain vanilla HDMI tends to increase clock jitter of signals transmitted over it so more design and parts resources will need to be expended to clean ups it's act. Then there is the operational aspects like what does my stereo dac do if all the data streams coming over the link are multichannel? Play left and right only and let the user wonder what happened to the singer in the center channel or do an automatic mix of center into L & R? Or mute until a stereo signal is on the link? How complex shall we make the user interface to imform you of these issues and support setup options?
And those are just the initial high points of the HDMI minefield. The short answer is its a tall order for companies in the high-end audio niche .
