How likely is it that these companies can be compelled to turn over their SSL private keys via FISA court?

Isn't the whole point of all this outrage that NSA have equipment or data exchange arrangements with GMail etc. so that SSL is irrelevant?

"Isn't the whole point of all this outrage that NSA have equipment or data exchange arrangements with GMail etc. so that SSL is irrelevant" Yes which is why the NSA needs the cooperation of the companies, since this info can't be gotten just by listening on the wire.