Iranian Regime Wants To Be "Serious"

According to every major newspaper the Iranian regime says today, in a very short version, that they are ready to enter "serious negotiations'' with the permament UN Security Council member states and Germany.

So what does this mean?

1. Iran has never entered a serious negotiation on its nuclear program before?
2. This time they really intend to tell the UN Security Council to fuck off FOREVER?
3. This time they really want to comply with international and legitimate demands of Iranian cooperation?
4. This time they will once again play with the UN and continue the enrichment process?
5. This time they will tell the UN that the sons and daughters of the Islamic Revolution will definitely build that damn bomb so that their nutcase president can put some real weight behind his fuming antisemitism?
6. Or what?