Everything is tight at the top so they could drop right out again, but this recent streak has brought them from 6th in the league to 3rd in points. They also have the second best goal differential.
Pittsburgh is idle tonight, so a win could put the Bruins in first place in the conference and second in the NHL (though Pittsburgh will have a game in hand).
I tend to agree with cshea, although home ice could be important in the conference finals. But you have to win two rounds to even get there, so it's probably more important to have the best team you can on the ice than to worry about that.