You're exactly right and this "agreement" gives the President the option to have FISA review it. He'll probably send FISA a couple of border line test cases to see how they're leaning on that day and then if it looks favorable he'll let them see the whole program.
I have a feeling that another reason Bush is doing this..is because of that lousy decision by the SCOTUS last week...
He is probably afraid that Specter and gang would send his program to the SCOTUS, hoping for an equally BAD decision that would go their way, instead of the President's.