I've been thinking of using a IR repeater meant for making an IR TV remote control aSat/Cable boxin another room. They're simple setups that have an IR receiver that converts the signal to RF sends it to a receiver that repeats the IR signal. I'm not sure if it would work. I'm pretty sure I read somewhere that Canon's slaves/masters use a "near IR" signal. Latency could also be an issue. BUT, if this worked you should maintain TTL plus improve the capabilities of the native Canon system.
Any thoughts? Anyone have what they would need for an experiment?