Massachusetts was weird in 2008. It was the only non-southern non-ticket state in which McCain got more votes than Bush 04 did. Also it was one of just 5 states where Obama under performed Kerry's %. I was wondering if there might be reverse coattails and some Brown voters cross and support Romney. Of course only time will tell. It'll be really interesting to see if Romney can win Plymouth or Barnstable counties
I doubt there are going to be reverse coattails from someone who's an even chance to win his own race.
Why? Romney is certain to do worse than Brown, and unlike Brown he probably won't be doing any real campaigning there, just whatever leaks into Massachusetts from his campaign in New Hampshire. If Romney is campaigning in Massachusetts it'll be because he thinks the Presidential race is decided (one way or the other) and he needs to campaign downticket to boost GOP prospects in the Congress.