I'd guess the CW will be that McCain won on points, with nothing close to a knockout, and I'd echo that judgment. McCain had Obama on the defensive over earmark requests and his $800 billion in new spending, then later on the surge and those rogue-leader meetings. Obama did do a decent job shifting the focus back to the original invasion of Iraq and was effective at highlighting Bush's serial foreign-policy failures (North Korean nukes, Iranian centrifuges, growing Chinese influence), but was generally less punchy and more reactive.
My biggest problem with Obama is that he cedes almost all the emotional ground to McCain. For my money, the exchange that defined the debate was McCain sarcastically suggesting Obama would just tell Ahmadinejad "no" when he threatens to annihilate Israel. Obama tried to interrupt McCain several times during this mini-rant, then just kind of let the matter drop when he had a chance to respond. What he needed to do was look straight into the camera and inject a little emotion of his own. Something like, "Israel is one of our most loyal allies in the world. Their security is absolutely sacred to me. And if Mahmoud Ahmadinejad or any other tin-pot dictator thinks he can threaten Israel in my presence or anywhere else, he's in for a rude awakening. I would leave absolutely no doubt in his mind how we treat countries looking for fights with our allies."
Sure, it wasn't Dukakis whiffing on his wife's hypothetical murder. But it was a missed opportunity to stand up both to McCain, who couldn't stop sneering, and to potential adversaries. Obama missed similar opportunities all night long.