That would make good sense for both sides.

He does have the largest charging system in the US. And he is building a battery megafactory (that will bring costs down by ten fold if not a hundred fold).

The more cars using his batteries and his power stations, the better chance he has to win as big as Rockefeller won at the dawn of the gas vehicle.

But it turned out that it had to be him (building the megafactory), since it was two years from his prediction to when he went for it.

So I bet your implication is correct, this will be with regards to the battery interface and charging subsystems.

If you look at their patents, a lot of it is UI stuff but their fast charging patents and their charging connector patents would be perfect to release: http://www.faqs.org/patents/assignee/tesla-motors-inc/

he'll actually pay other automakers to use Tesla's technology. or offer incentives in other ways to encourage them to play with him. some friendly competition at this stage would be a good thing, and not competition at all.