There are a few scenarios floating around about how Brown can make it back into the Senate. The big one is that Kerry is appointed as Secretary of State which then allows Brown to run for Senate again in a special election. However, the latest news seems to indicate that someone else is in top consideration for a that post.
Another scenario is that Kerry (68), whose term is up in 2014, decides to retire. That gets a mention in the Blogging Heads video posted below. An interesting part of the video is a discussion about whether Brown would continue to run as a Republican as it would still make reelection a dicey proposition, or if would switch parties to make a win a sure thing. Would Scott Brown actually become a moderate Democrat to win reelection? Would he retain your vote?