I think Putin is done annexing Ukraine and is now offering Obama a way to save face, i.e, to claim that he (Obama) successfully defused a potential international crisis.
Putin is doing what he wanted to do from day one.
He knew that the West would be satisfied if only he stopped at Crimea. Putin feigns the move into Ukraine proper, the West gets angst, and then he pulls back. There, crisis averted, the West returns to happy talk.
Crimea? What’s this about Crimea?