They might as well nominate Romney now.
Either Obama or Romney will be the next president. After the inauguration, there will be pretty speeches, high hopes, barbs thrown back and forth, then nothing much will change. The recession will gradually ease, and Republicans will give the credit to Romney (if he wins, that is), since his party and his name both start with R. Democrats will maintain that it was all Obama and his bailouts.
But, the next recession will still happen, the Middle East will still be a hotbed of nutters, Iran will still get nukes to brandish at the rest of the world, illegals will still stream across the borders, health care will continue to increase in cost, the debt will continue to grow, and the middle class will continue to shrink.
At least, that's my pessimistic view of the future. Maybe Mitt will prove me wrong.
My cynicism, after all, proves wrong as much as 1% of the time.