https://theleafsnation.com/2017/07/29/the-good-and-bad-of-summer-2017-so-far-atlantic-division/
I've been meaning to poke at this, but I didn't want to do my own research; fortunately, TLN (et al) have done it for me.
This is Montreal's work this offseason so far:
IN: Jonathan Drouin, Karl Alzner, Ales Hemsky, David Schlemko, Mark Streit, Matt Taormina, Joe Morrow, Peter Holland 8), Byron Froese ;D.
OUT: Alex Radulov, Alexei Emelin, Nathan Beaulieu, Mikhail Sergachev, Joel Hanley, Brian Flynn, Stefan Matteau, Dwight King, Andrei Markov, Nikita Nesterov, Steve Ott.
and (very defensibly, but maybe not that wisely) handcuffed themselves to an aging Carey Price.
Ottawa replaced the Marc Methot that they loved and lost rather easily to Vegas with the really old Oduya, but really haven't done anything to improve or surround Karlsson with better support.
Boston is treading water in a relatively good spot (their defense is turning over to the youth, and they are pretty good).
Florida is a poop emoji movie behind the scenes, but on the ice, if they can stave off injuries, are still quite good.
Tampa, for some reason, got Dan Girardi, but they're still probably the scariest team in our division.
Detroit is LOLs.
Buffalo has no identity, other than being the team that has no identity, but they have weapons up front.
The Leafs are largely unchanged, other than getting older overall but picking up vets with wheels. The wagon is still being dragged largely by the Big Three + Rielly and their slightly older shepherds (Gardiner, Kadri, JvR, Bozak).