Now that the media seems to have the story straight-ish, it seems that the US has a "two-track" approach - one that seeks to pin down negotiations while at the same time tightening sanctions for leverage. This story seems to be saying that bilateral negotiations have been agreed to in principle between Iran and the US, but until an actual negotiation is set, things proceed as they have been.
U.S. says willing to meet with Iran on nukes but no talks set
the United States and Iran have agreed in principle to hold one-on-one negotiations on Iran's nuclear program but the White House quickly denied that any talks had been set...
The Times, quoting unnamed Obama administration officials, said earlier on Saturday the two sides had agreed to bilateral negotiations after secret exchanges between U.S. and Iranian officials. The newspaper later said the agreement was "in principle."
Regarding the two track approach:
The Times story quoted an unnamed senior administration official as saying the United States had reached the agreement for bilateral talks with senior Iranian officials who report to Supreme Leader Ayatollah Ali Khamenei.
But the White House said the Obama administration was intent on its current "two-track" course, which involves both diplomatic engagement and a tightening network of international sanctions to pressure Iran.
If Reuters' current portrayal of the story turns out to be an accurate one, this is a big f'ing deal.