Andrew Sullivan has been interesting.
As far as what happens, Romney made it through an entire round of interviews today and I really doubt that anyone asked why he doesn't release more records while referencing his father. Remember his father released 12 years of records and said specifically: "one year could be a fluke, done for show." with regards to politicians releasing tax returns.
He will be pressured continuously for this week. He will then have a choice:
A) refer people to the statements, fact check/Glen Kessler's WaPo account and challenge reporters to repeat Obama's talking points in this is partisan attack. By the way, it is disgusting and shameful that Obama would call Gov. Romney a felon.
B) take it to Sunday talk, where by this time there will be prominent Republicans calling for concessions like releasing additional tax returns etc. He will most likely be asked about why he has not chosen to release nearly as many documents as his father. It is a tough question to answer and it is a no-win and Romney isn't going to win people over with his personality/Bill Clinton lip bite to distract from the substance.
Unless something else comes out, Romney isn't going to change his approach and this will not derail him. If there are other shoes to drop or Romney's team screws up, then it could be more damaging. Either way, the Bain attacks from Obama are going to be unending and brutal and they will cost Romney votes, but that has almost nothing to do with what happened this week if this is it. The media is weak and has a short attention span, they won't go on and on for a month with this story if there are no developments and Romney turtles up.