You've gotta check out Pocket Wizard's web site to see how Pocket Wizard is FINALLY answering the call to a quality product for doing TTL without a cord or infrared. This is the product we've been waiting for.
This is the product RadioPoppers should have been, but instead they seem more like garage project hacks that went from being a bargain to nearly as expensive as PocketWizards. I'm glad they existed to help Pocket Wizard get off its laurels and start doing something that should have been done years ago, but I'm optimistic that this will be a better solution long-term.
This is the transmitter that mounts to your camera hot shoe and still supports you putting a flash on top of that (although there appears to be an issue with the 5D Mark II under that scenario).
This is a replacement for your Plus II or MultiMax to have full TTL support - woohoo!!!!