I read on another board that the cutoff date for nominations was about 11 days after Obama took the oath of office.
Can anyone confirm this?
That's true.
However, it's important to remember that Obama existed before he was President - apparently the committee thought he at the very least seemed promising. He did vote against the Iraq war, and there may have been other actions they took into consideration.
And the decision still took almost a year, letting them base their decision on how he followed up his previous words and actions with the greater abilities of the President.
Remember, most analysis is saying that the Prize was awarded to give a boost to Obama's current efforts, not so much as a reward for past deeds. Over the intervening year Obama
has successfully improved international relations with a variety of countries and has demonstrated a commitment to diplomacy over the idiotic policies of the past. He's made significant progress in scaling down the mounting tensions between the US and Russia by removing missile defense sites and negotiating nuclear disarmament - that's not insignificant, considering that US relations with Russia were heading back towards Cold War levels under Bush.
He's definitely not the most deserving person to ever win the Prize, but neither was it completely undeserved and random.