I've been trying to follow what Nissan and Mitsubishi are doing as far as V2H or vehicle to grid goes. From what I've read, they are both using the CHAdeMO port, but had different standards as far as how to convince the car to keep the contactor closed. They are now working together to create a standard for pulling power out of the CHAdeMO port. See here
in Japanese or here
for a translation.
The 1.0.0 CHAdeMO spec was released on January 31st that may include bidirectional compatibility. All the '11s and I believe the '12s conform to the 0.9 spec which does not officially include the ability to pull from the pack.
Also see Mitsubishi's "power box" which is an off grid inverter rated for 1.5kW: here
youtube video on it.
I've seriously considered getting the iMiEV instead of the Leaf due to the fact that I could be the first to do vehicle to grid with a production vehicle. I'd import a power box and monitor and emulate the CAN messages and hook it up to my isolated grid tie inverter. I'm very serious about vehicle to grid.
Basically, if you want to learn more about this stuff, you've got to know Japanese or snuggle up with translate.google.com