Bruins basics:
Let's start with the losses. Jagr, to my honest surprise, wasn't invited back and is now in New Jersey. Nathan Horton is gone, signing with the Blue Jackets. Backup goalie Anton Khudobin signed with the Canes. Tyler Seguin is off to Dallas, and took Rich Peverly with him. And perhaps most painful to longtime B's fans, Andrew Ference is now the new captain of the Edmonton Oilers. Most other roster losses were pretty minor stuff like Wade Redden not returning.
And the gains? Trading off party-boy Seguin produced Loui Ericksson in return. That's huge. Seguin was a dingus, but he produced a lot of points, so if you're going to lose him you have to get something significant in reply. Ericksson is a guy I've admired for a long time, glad to have him on board. Chad Johnson is looking like he's the new backup to replace Khudobin, I'll reserve judgement until I've seen him play a bit. Ference gets replaced by one of the multitude of young defensemen the B's have had going (expect to see a lot more of Dougie Hamilton this year!). And of course, no talk of changes in Boston is complete without mentioning Jarome Iginla, although I'm not going to believe it until the puck drops and he's in a spoked-B jersey. Until then, there's too much chance that the Penguins sneak in again.
So, really, call it a wash. They lost some major talent in the offseason, they gained back quite a bit, and while they're a little older up front than they were last year they're also still talented, and got younger and arguably more talented on the back end (with all apologies to Ference).
I predict the Bruins will be a force to be reckoned with in the East again, almost certainly in the playoffs, probably a high seed, and have as good of a chance at the Cup as any team in the NHL.