The big difference between Obama and Romney will be in the makeup of the Supreme Court in four years. There will most likely be at least one retirement (Ginsburg) in that time and filling that spot could tip the court further right or leave it with its current makeup. If Scalia also retires, the court could go to the left if Obama gets re-elected.
Otherwise I think the next four years will look like the last four years no matter who gets elected; not much getting done and the economy continuing a weak recovery at best. I'll vote for Obama because I feel the SC is best left as it is or a tad further left. Plus I think Romney has no honor and will do whatever is good for Romney. I just don't like him.
Now if the GOP could convince Tom Ridge to run one of these years....