Wouldn't this be a good trial balloon for a prize?
If Griffin is worried that the big space companies can't develop methane engines within a resonable budget, then shouldn't Nasa offer some prize money to see what the "new kids" can do? Offer a prize of around $10-$20 million for a methane powered engine. If no one delivers then nothing is lost, but if they do, then Nasa gets a new engine for a bargain and an emerging comapany gets some added clout. Sounds like a plan to me.