Having been to Berlin and Littleton with McCain about a year and a half ago, as I recall, this area is pretty far north -- and seems to be pretty conservative.
To my knowledge, this is the first time Todd Palin has gone out on his own. At least, I've always seen him campaigning with Sarah. Look for him to hit other states, including (my prediction) Michigan.
It should also be noted that he's doing a factory tour. I'm told that Todd has always done a lot of work on behalf of blue-collar issues (VoTech education, etc.) as a result of his job as an oilfield worker...In other words, this is his wheelhouse.
If the McCain campaign continues going this route, Todd has the potential to be a very valuable weapon when it comes to voters who have blue collar jobs, are union members, etc (a key demographic in a lot of places like Ohio).
If I'm the McCain campaign, I would definitely be using Todd in exactly this manner...the more photo-ops involving hard-hats the better.