Let's see, for the first time in who knows how long, a Republican is in a Massachusetts Senate seat instead of a liberal Democrat. "Ted Kennedy's seat" no less, that's quite a feat since everybody assumed a liberal Democrat would naturally be the successor to that seat. And you know there was no way a staunch conservative could have been elected.
Overall I'd say Brown was quite a bit of progress in the right direction.
I just looked it up, their last Republican senator was Edward Brooke in the 70s, and he was pretty liberal too.