HDMI's loose nature is particularly annoying since I saw the SATA cables that came with my last motherboard. SATA is a similar connector type to HDMI, just a bit smaller, and these cables had a positive latching design via a little spring-loaded piece of metal. The concept would have been very easy to add to HDMI.

Otherwise I would love to see a return to BNC connectors. I hear there's a professional HD system that does HD video and 5.1 audio over a single coaxial cable. I'm sure custom installers would rather use standard RG6 than premade HDMI...