Perhaps Boris doesn't.
Last night's Standard interview hinting publicly that he might not run again has today sparked a remarkable amount of activity and speculation among London Tories, who the Standard reports are preparing for a post-Boris future. Shaun Bailey openly suggests he would be in for the nomination.
Over on Liberal Conspiracy, I look at why Boris might worry about whether a second term could make it harder for him to become Prime Minister, his ultimate goal in politics.
Still, I think he'll run again.
On the Labour side, Ken Livingstone has now said that he will contest the nomination again, some three decades after he first ran London. I think the party should commit to an open primary for the nomination.
Will Boris run? Could he be beaten? And who would you like to see in the race?