HDMI was built carry digital video and sound throw a unique cable ... this is a mix between DVI and digital sound AND (the last but least !), this is encrypted !!! Because the idea is NOT TO BE ABLE to copy using this support ... So about your question ...
Be sure that it will take a lot of time before we can see HDMI support (don't know about output) as an input on a computer (and sure it wouldn't be ... errr ... legal :wink: )
By the way, I think the idea with pluto is much more to use the IP protocol instead of uncompressed digital data on a dedicated support. The only HDMI plugs we ought to see are on DVD players, displays ... , that we can manage using Pluto.