It's father's day weekend so I'll hold my own comments till Monday. Nor is the Rouhani (Rowhani, Ruhani, Rohani, etc.) first-round win the only weekend news, but it's the most surprising. Meanwhile, early takes from others:
Farideh Farhi, "Iranians Vote for Hope and a Change of Course."
Shaul Bakhash for the Wilson Center, "Rouhani's Surprise Election."
Scott Peterson at CSM, "Hassan Rohani is Iran's Next President. What Will Change?."