Maybe. But the economy is #1 concern right now, esp. 401(k)s.
Voters saw the debates, but the 3rd is what voters will most remember, and it dealt with economic themes such. McCain destroyed Obama. Couple with that the Joe the Plumber video and the recent 2001 audio, and we have what the undecided/independents already intuitively know about Obama: he will take from the earners and give to the non-earners.
McCain needs to hit Obama hard on Dems wanting to tax 401(k)s. His closing argument, as was his theme on the 3rd debate, should be about how he is a strong leader of accomplishments on economic issues, reassure people he can get the job done. Polls are already shifting towards McCAin when he uses this theme.
Obama has not sealed the deal. His ad on Wed. will turn people off, due to over-saturation of his ads and his empty message of "hope" and "change." We already know he will lie about is tax policies. This will reinforce that perception.
For most, but not for all. Most people are capable of considering more than one issue in making up their minds. Also please note that the McCain campaign IS spending all of its effort on economic issues, this ad is being run by an independent organization, which it is illegal for McCain to have any contact with.