By way of comparison, consider President George H.W. Bush. In 1988, he won a slightly larger share of the popular and electoral vote than President Obama in 2008:
After the 1991 American victory in Desert Storm, President Bush's Gallup approval rating reached 89%. For much of that year, there was speculation that his popularity was keeping strong Democrats out of contention, leaving a weak field of challengers. But in 1992, largely because of a bad economy, he lost to Bill Clinton. With Perot in the race, President Bush got the smallest percentage of the popular vote of any sitting president since Taft.
There is no guarantee that history will repeat itself. Perhaps President Obama will win big. The point is that it is far too early to make any forecasts about the outcome of the presidential election.