I believe the comparison to Kerry's constant drumming of the Vietnam War Hero drum, in conjunction with his repeated insistance that he, himself, committed a whole slew of war crimes in 4 months to the carnage the Clinton administration caused is important, whether he chooses Hillary or not. It's a form of hedging our political bets, IMO.
Honestly, I don't see how he could choose Hillary! at all, since he voted for military action in Iraq and so did Hillary!, but Hanoi John has flip-flopped and says he's always been against military action in Iraq, while Hillary! hasn't. Though she did tell the the troops their country doesn't support them and they're all gonna die over there for nothing during her Thanksgiving photo-op, Hanoi Jane-style trip to Afghanistan and Iraq last year.
She even ticked off her own base....though no doubt they forgot and forgave her for it by now.
Hillary spent a lot of time restyling her packaging to appear to be a moderate who believes in strong defense. She can't afford to move (in public) back to the rabid left with Kerry without destroying her political career. Kerry's been pandering to the anti-war crowd by beating the Vietnam drum and will lose those votes if he nominates Hillary.
Talk about painting yourself into a corner.
IMO, he'll go for Clark, or perhaps the trial lawyer....though if he asked his significant other, John McCain, to switch parties and run with him, McCain would probably do it.