Well, game changer is a vauge term. I agree wholeheartedly that everything is being blown completely out of proportion.
In a way this was a game change in that the situation has changed. Romney's campaign is no longer in danger of collapsing and Obama doesn't look quite as unstoppable. On the other hand, the fundamentals of the race are the same. The economy sucks but is slowly recovering, Romney is unlikabe, Obama is very likable, etc.. Obama still has the advantage overall.
I would actually say that Voters have been looking for an viable alternative to Obama all year, and Romney has now given voters hope for an alternative. The pieces have always been in place for a Romney victory, but no one was sure about the leader to put them all together. Romney appears to be someone "who can Save America" and the polls next week will show Romney tied or leading Obama in the swing states.
As long as Romney keeps up his A game for the next month, he will win the election.