According to capgeek.com, the Bruins are currently (with Savard on LTIR), 10 million plus under the salary cap for this season. With all this extra money the Bruins are one of the only contending teams that could add a major core piece to their roster without having to dump players for salary cap reasons this offseason. 
The player I have wanted the Bruins to trade for is Jerome Iginla. He would instantly bring goal scoring, veteran leadership, toughness, power play goal scoring, the will to win, and could replace Horton’s spot on the line with Krecji and Lucic. Which puts everyone else back in their place on the other lines. Iginla is the big name that could, fit right in and deliver a cup or two to Boston and would not disappoint the way Kaberle did. Selanne is a fit but he is not a physical enough player to replace Horton’s forechecking, and Rick Nash is going to cost way too much to acquire for the same production Iginla would give you the next two postseasons.  
Calgary is in ninth place in the west, and they have been just good enough to make the playoffs or just miss for years now. Calgary is also one of the teams with the highest payrolls and least cap space. They have little to no prospects in their system, and lack the draft picks to rebuild. The only way Calgary can rebuild and become a legitimate contender is to move some of their salary and acquire some prospects and draft picks in return. They would have to give up on this season but, in all honesty the ninth place Flames have no shot of winning a cup as currently constituted.
The Bruins have the pieces and draft picks to make a fair offer to Calgary for Iginla. Last season it was rumored they would have taken either Rask or Horton straight up for Iginla.
Bruins have to offer:
Nathan Horton, If Bruins can move him for Iginla then they should do it, gives Calgary a younger player, saves them 3 million in cap space, both of which help Calgary to build. If Bruins trade for Iginla, either Horton will be a part of the deal or will have to get traded this offseason and put on LTIR for the remainder of this season. Bruins could call it, wink wink, a player to be named later, and then when Horton comes back from injury he is the player that Calgary gets later. 
 Obviously Horton alone would not be enough. So Bruins need to add a combo of the following:
Draft picks in 2012: Bruins 1st Round Pick, Bruins 2nd Rounder, Colorado’s 2nd rounder, WAS 2nd rounder in 2012 or 2013, Bos 3rd, Bos 4th, Carolina’s 4th, etc. A combo of a first round draft pick, and two second rounders should be enough alone to acquire Iginla. They gave up a first round and second round pick for Kaberle, traded guys like Mark Stuart away to make cap room, all for Kaberle who sucked and we all knew that before the trade, why woudln’t you give that up and more for Iginla who is the perfect fit and you get a whole extra season than you had Kaberle? 
Top Prospects that I would trade for Iginla: Ryan Spooner, Jordan Caron, Zach Hamill, Alexander Khokhlachev, Jared Knight, Steve Kampfer, Matt Bartkowski, Andrew Bonardchuk, etc. Pretty much anyone but Doug Hamilton.I am sure if the Bruins made an offer to Calgary with some of those prospects, Horton and draft picks they would at the very least consider it.Yes, Calgary is still in contention, in ninth place, but they have no hope of winning the cup and rebuilding around a 36 year old Iginla is not going to happen when they have no cap room, no draft picks and no prospects. Time to make a deal that will help both organizations.Furthermore, all this talk of trading David Krecji, Tuuka Rask, Tim Thomas, is ludicrous. The Bruins need those core players to win the cup now and for the next few years. Krecji led the team in points last postseason, just needs his line with Lucic and the Horton of last year, put back together to be effective. Thomas is your starting goalie this postseason and Tukka will be the starting goalie for the next 11 postseasons, the only way one of them is leaving is if Thomas retires or takes a bigger contract from another team when his current one expires. 

 Wow!… take a deep breath Deano… first, let me start with Iginla.. good fit, like the idea for two years.. that’s it!.. ok, we’re off to a good start.. ditching Horton to make it happen.. i like the idea.. but i don’t run the Calgary Flames organization..i am a Bruins fan, and it sounds good from my position in this.. but seriously, Horton has concussed twice now in less than a year, why would Calgary consider moving their “franchise player” for him? if you want to say Lucic, which i am not advocating, i think you’d get Calgary’s attention.. so, with that said, it will cost you Krecji, or Thomas or any one of the better players on the Bruins to make that deal happen, unless Calgary just wants to do a Bourque deal, just so he can win another cup…  I doubt they will be willing to do that… on paper, your offer sounds great.. in reality, it just doesn’t make sense…too bad..:(