What's driving Alan?

Alan Milburn has a big set-piece interview in The Speccie today, and it repeats what's becoming an emerging trend (and, Mr Fraser Nelson, this is not Milburn's first interview since the election, he's spoken to local media at some length):

Mr Milburn has a proposal. ‘The way I would do that is by dramatically cutting the size of Whitehall. I would slash it over and above what is being done by a quarter.’ A quarter? Yes, I heard him right. ‘If you are serious about fundamentally transforming how power is held in this country, you must start at the top,’ he says. ‘The bigger the machine, the more it will do.’ So Mr Milburn’s post-Blair agenda would start by cutting government staff, using a rationale that recalls Reagan’s ‘starve the beast’ tactics. Outside agencies could advise ministers, instead of the Civil Service.

So, what's Milburn up to? Is he:

• The keeper of the Blairite flame?
• A viable post-Brown leadership candidate for after a lost election?
• Keeping the seat warm for another Blairite candidate (Miliband? Hutton? Even Purnell?)
• Just having a real good time with an occasional stir?
• Running on Clarke-style bile and bitterness?
• All of the above?