Boy you seem to not know how things really work do you?
The 4473 MUST record the the serial number and the gun information being sold. As well as quite a bit of personal info of the person buying it and their physical description. Of course the personal info must be done to do a background check.
However, while there is no official "registry" those records are stored. Indefinitely. Sure the ability to have a program pull an SQL query for a quick access to the information won't be available, but that does not mean the information can not be tracked down. That's how it works today. Did you not know during hurricane Katrina in New Orleans, the major of the city made police go DOOR TO DOOR, without warrants or anything, to bust down doors and confiscate weapons from law abiding citizens? The local government there did that. They used to records that must be kept from FFL transactions to know who own what and where. Much of those guns have still not been properly returned to their legal owners to this day.
THAT is what the fight is about. You can try to paint it a different color and say one thing, but it's still all lipstick on a pig.
http://en.wikipedia.org/wiki/Criticism_of_government_response_to_Hurricane_Katrina
Go read and educate yourself.