In all honesty I think if they'd actually wanted to get something passed they wouldn't have gone to Feinstein. I think this is just the President making noise to placate the anti-gunners.
That being said, if something did get passed there's no way of telling what would happen. Maybe stuff would be grandfathered in, maybe not. I've been trying not to let it effect me one way or the other.
si vis pacem para bellum