A good collection of commentaries here.
More here, including this gem from David Von Drehle of Time:
"McCain Threw the Sink — and Plumber — But Obama Doesn't Falter" The problem for McCain is that no matter how hard or how crisply he punched, it could not last. In the end, the gravity of the debate returned to Barack Obama. The turning point was when McCain finally brought up the issue of Obama's ties to former the anti-Vietnam War terrorist William Ayers. All he accomplished was to swing the spotlight from himself back to the engaging newcomer. Predictably, Obama had a mild answer ready-as straightforward and uncontroversial as it was soothing… Mostly he tried to say that Obama-change is dangerous. Across the table, there sat Obama, looking not very dangerous.
- Garry J. Wise, Toronto