I'm looking at this same problem with my own home theater I thought I future-proofed when I had the room built in 2002 with all the relevant cables going from the wall on the end of the room with the components up to and across the ceiling and to the place on the opposite wall where my ceiling-mounted Sanyo PLV-HT60 would hang. Now it is 2014 and the Sanyo has been left unused for a while due to an irritating misalignment in the red and green of the picture that I wasn't able to fix using the service menu, and I have just bought a new BenQ W1070 1080P 3D Home Theater Projector to replace it. However, the cables that were installed are: component, composite, VGA and BNC, to match what the Sanyo had at the time, needless to say there is NO HDMI.
I ordered a 25' HDMI cable, but don't relish the thought of trying to cut open the wall and ceiling (and I can't remember with way the studs and beams go, but they probably had to drill holes in them to get the wires through) to snake the new cable in. I may look at wireless HDMI or just hiding the external cable along the corners as much as I can (25' may not be enough for that option though.)