They also sent Steve Kampfer to Minnesota for defenseman Greg Zanon.
Rolston played with the Bruins back in the early 2000s. He scored a career high 31 in 2001-02. He's got 4 goals and 5 assists in 49 games with the Islanders this year, so I don't know how much he has left in the tank. He adds depth to the bottom end of the depth chart.
Mottau won the Hobey Baker Award (college hockey's Heisman) his senior year at Boston College in 2000. Greg Zanon is similar to Mottau. Neither of these guys will contribute much on offense. Which I'm happy about. The Bruins need solid defensemen that don't make mistakes. These guys are the anti-Tomas Kaberles.
And with Boychuk down, the Bruins needed depth at the blue-line.
These aren't exciting moves. These moves don't make the Bruins much stronger. They address potential weaknesses. I'll take Rolston over Josh Hennessy. I'll take Zanon or Mottau over Kampfer. And maybe even over Corvo.