Iran and the P5+1 have announced a 7 month extension of their talks on a final nuclear deal today, taking the process potentially through June of 2015. Today was the deadline, and both sides agreed more time was needed for the talks.
It was not surprising that another extension was needed, but it was surprising that it was agreed upon for such a long time, particularly with reports over the weekend of significant progress on some sticking points.
Either way, the talks have a secondary deadline of January, when the new US Senate takes power, as they intend to grant themselves veto power over any negotiations, and are stacked with hawks opposed to the talks on general principle.
The Senate would do this by deliberately violating the terms of the deal with new sanctions against Iran, if any deal was reached. They could theoretically also do this after the fact if a deal was reached before January, but it would be more controversial.