Might rather see it the other way around - Nvidia getting license to create products with x86(_64) CPUs integrated in the silicon. Nvidia are the big boy in this transaction and they'll get what they want out of it. But I can see the attraction for Intel.
I don't think they can, as AFAIK the agreement for x86_64 is that Intel and AMD cannot change hands. AMD will surely fight this tooth and nail in the courts
But with the state of the courts today... who knows..
Yes indeed. It's still a step in that direction that opens up a bunch of communication channels between the execs of the two companies. Things move slowly.