This has got a lot of positive press for Brown. It wasn't just Politico and conservative websites, but the likes of NPR, the Washington Post Even if it's a bad poll, it could end up getting him a second look.
It's worth noting that the primary isn't officially over yet. Brown's opponents included a former US Senator from New Hampshire (albeit a wacky one) and a wealthy former state senator. A competitive poll reinforces Brown's top arguments. He might have been weaker if every poll showed him down 8-12 points against Shaheen.
And I agree with your second part - if Smith dropped out (since he's not raising any funds) and let the rest of the GOP unite behind Rubens, Brown would have a very real chance of getting kicked out of the primary. He's much more in-tune with New Hampshire's views than Brown, and dare I say has a better chance at beating Shaheen. While the national media's been talking about how this is a tie race because of one sketchy poll from a firm that should only be trusted on election day, on the ground here, Mitt Romney and John McCain's veterans director (who's a big presence among vets, especially in Nashua) just endorsed her. Not only that, but he was one of Dubya's campaign chairs in NH, and his reason for crossing the aisle was because "Jeanne Shaheen puts New Hampshire first". If that's not a thinly-veiled shot at Brown, I don't know what is.
Obviously the national media, and this one poll say it's a tie race, but on the ground, New Hampshire is getting the message clear: Jeanne Shaheen is in this race for New Hampshire. Scott Brown is in it for Scott Brown. And you can't disguise that, no matter how unpopular Obama is.
