I hear Barack Obama retook the oath of office because the right-wing blognuts have been turning themselves inside out speculating that he is not the rightful President because he didn't get the oath correct as written in the Constitution.
First, let's get one thing straight. The 20th Amendment to the Constitution specifies that the new President's term begins at noon on that day, regardless of whether he takes an oath or not.
Second, the oath of office in the Constitution is specified as:
"I do solemnly swear (or affirm) that I will faithfully execute the office of president of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."
Now, you will note that there is no "So help me, God" on the end, although almost all Presidents have added it. So does this mean, right-wing nutballs, that every President who added "So help me, God" was not the rightful President? Hmmm??
Thirdly, you guys lost. Get over it. We had to live with George Bush for eight very long years. It's your turn.