According to this article, the Obama and Romney campaigns are insisting on final review of all quotes before they they will agree to allow interviews or briefings.
Source: New York Times
The push and pull over what is on the record is one of journalism’s perennial battles. But those negotiations typically took place case by case, free from the red pens of press minders. Now, with a millisecond Twitter news cycle and an unforgiving, gaffe-obsessed media culture, politicians and their advisers are routinely demanding that reporters allow them final editing power over any published quotations.