Clearly, I cannot say this with 100% certainty, but logic always prevails, and this is the only reasoning behind the waiving of Niklas Hagman that is, well, reasonable. The move of sending Niklas Hagman down to the minors in and of itself is somewhat pointless. No call-up will have a higher upside than Hagman right now, and it seems incredibly unlikely that he's going to be picked up off of waivers at $3M for both this season and the next. That leaves one reason for this move: cap space.
As of right now the Calgary Flames can afford a $4.58M cap hit at the trade deadline (all salary numbers, of course, from Capgeek). That's certainly not awful, and could lend itself to taking on salary or picking up a solid player. But say Jay Feaster wants to make a couple moves. Say he gets plenty of offers thrown at him and decides to take more than a couple (for better or worse)--we really don't have the cap space for that. Or maybe he wants to target a super star--first, there's the hope that Hagman's salary is just gone straight up: someone claims him.
Here lies the problem however: if the Flames were to send Niklas Hagman down to the Heat immediately upon clearing waivers and the potential trade or trades fell through--they'd need him back, putting him on re-entry waivers.
This leaves the Flames with the very high risk of Hagman getting picked up at $1.5M per for the rest of this season and all of the next. And that's rough--paying for a player who is no longer on your roster in any way, shape or form in both salary and cap space.
So what will the Flames do? The solution is actually quite elegant: place Niklas Hagman on waivers now, but don't reassign him until the cap space is absolutely needed. The reassignment period lasts for a total of 30 days or 10 games, whichever comes first, enabling Jay Feaster to wait to reassign Hagman until the capspace is absolutely necessary.
Of course, I don't have have the ear of Jay Feaster, and so I could be proven completely wrong by Niklas Hagman (or J.R. Ewing, as he's known in my heart) being assigned immediately upon clearing waivers, or my point could be rendered completely moot by a team actually deciding he's worth the pick-up. But until that happens, we'll just have to wait.