So here's my take, which I know you have been awaiting: I think he should be himself. Obama is not Rambo and all the calls for him to "take the gloves off" and so forth call for him to act against type. Obama is a semi-geeky policy wonk. He plays basketball quite well, but so do more than a few eggheads.
So he should embrace who he is, and talk taxes. I have been going door-to-door in the Tidewater since July, and even in this bastion of militarism, the economy is a big concern. People say they are worried about taxes, so they can't vote for Obama. (Thanks, uncritical stenographers at the mainstream media.)
I think Obama could score big with simple, short specifics-laden ads. People are looking for substance. (I am making up all the numbers that follow, but Obama, obviously, should use the real ones.)
"John McCain says I would raise your taxes, but he's not telling the truth. If you're a family making $45,000 a year, my plan would cut your federal taxes about $6,000. If your family brings home $65,000 a year, my proposal would let you keep $7,000 more of that by lowering your taxes."
"Now it's true I would raise some taxes--I would ask for more from wealthy Americans who have more: the five percent who make over $250,000 a year. Their taxes would go up. And that is why John McCain doesn't like my plan--his own taxes would go up.
"Here's a fact John McCain doesn't want you to know: the McCain family would get a tax cut of nearly $400,000 a year if the McCain tax proposal is adopted. The family that makes $45,000? They'd get their taxes cut $47."
"John McCain--a plan to cut his own taxes, not yours."