This was a very close debate.  Each candidate scored points, but no knockdowns, and no knockout.

• Barack Obama says John McCain wrong about Iraq 
• McCain says Obama "doesn't understand" some key issues 
• Candidates debate earmarks, taxes, economic plans

Up against McCain's clearly superior advantage in experience, Obama's performance illustrated that he was able to present  a clear contrast in his approach to restoring global leadership for the USA.
McCain sees the world through the prism of military victory, and Obama envisions a path of diplomacy supported by a strong military.

A CBS Preliminary post-debate poll of uncommitted voters produced these results:

• Forty percent of uncommitted voters who watched the debate tonight thought Barack Obama was the winner.
• Twenty-two percent thought John McCain won.
• Thirty-eight percent saw it as a draw.

Here is the Time/CNN Grade for each candidate:
Obama Overall:
Went for a solid, consistent performance to introduce himself to the country. He did not seem nervous, tentative, or intimidated by the event, and avoided mistakes from his weak debate performances during nomination season (a professorial tone and long winded answers). Standing comfortably on the stage with his rival, he showed he belonged - evocative of Reagan, circa 1980. He was so confident by the end that he reminded his biggest audience yet that his father was from Kenya. Two more performances like that and he will be very tough to beat on Election Day.  Overall grade: A-

McCain Overall:
McCain was McCain - evocative, intense, and at times emotional, but also vague, elliptical, and atonal. Failed to deliver his "country first versus Obama first" message cleanly, even when offered several opportunities. Surprisingly, did not talk much about "change," virtually ceding the dominant issue of the race. Overall grade: B-

This debate was supposed to highlight McCain's strength in foriegn policy experience.  Yet, Obama held his own, and scored the points he needed to score while taking McCain's best shot.  In this case a draw equals a win. 

McCain needed a clear win tonight, and Obama needed to hold his ground.  Obama held his ground while denying McCain the clear victory he needed.  This debate wasn't a clincher, but I believe Obama gained a few more uncommitted voters with his performance.  He is looking more presidential with each test. 

Perhaps the best place for a maverick is kicking up dust in the Senate.