The GOP is behind in money. As a result, the Democrats have a lot more TV ad time pre-purchased for the home stretch. Even if some additional money comes into the GOP coffers, they will have to pay much higher "last minute" rates and thus get less actual time for their dollars.
Meanwhile, the polls (everybody's polls) show that the GOP has yet to put away the Democrats in ten of thirteen key races.
It will be down to the wire whether you want to believe that or not. It is certainly not a done deal and a lot can happen in a month.
Oh, and a special note to Herb, Obama will be president either way. The GOP won't have a 60 vote majority to overcome a veto. Spin that!