Real Clear Politics has an interesting page that compares the state of the presidential race in national polls from 2008 with those of 2012 on a daily basis. These numbers represent the averages of all polls on that particular date.
And what do we find?
That the standing between Obama and Romney today is almost exactly the same as the standing between Obama and McCain in mid-August of that year.
On August 9, 2008, the numbers were Obama 46.9, McCain 43.3.
On August 9, 2012, the numbers are Obama 47.8, Romney 43.9.
In fact, Obama's lead against Romney is slightly larger than his lead over McCain, 3.9% vs. 3.6%.
And this is true for virtually all of July as well.
Conclusion? The dissatisfaction with the economy does not seem to be translating into an abandonment of the incumbent by the voters.
A few caveats: the chart doesn't account for voter enthusiasm, which might work against Obama, but it does include Rasmussen polls in the averages, which may mean Obama's numbers are actually marginally higher than those listed here.
Take it for what it's worth. I realize it's still early and that the state-by-state race is what really counts. But I think that this is a good indication that Obama is in a pretty decent position going into November. It certainly beats having it be the other way around.