First, we agree that the NHL's main problem is that it has the least amount of impact out of the 4 major sports leagues in the U.S., the weakest national brand? As in, the NHL needs to increase it's national brand (this does include "growing the game", but I am referring to the larger portion of that here).
Assuming that we do, then the move from Atlanta to Winnipeg, while almost certainly an improvement in the short term, is not beneficial and arguably harmful to this goal in the longterm.
In the short term, Winnipeg will probably make money (at least, more money than the Thrashers!). They will cause more interest in Canada (specifically Manitoba), and they will probably increase the value of sponsorship packages in Canada.
In the long term, however, these benefits do not outweigh the loss of the Atlanta market. The Atlanta market is huge, with both enormous population bases and corporate support, of which Winnipeg (indeed, the majority of NHL markets) cannot begin to compare.
A successful franchise in Atlanta will help to a much greater extent of the NHL's aims (national impact) than a successful franchise in Winnipeg. A successful franchise in Winnipeg reaches to a metro area of around 750,000 people; one in Atlanta reaches to a metro population of nearly 5.5 million. Further, Atlanta is one of the great sports hubs of the world, specifically the Braves, as they were labeled "America's Team".
Basically, the way I see it, while Winnipeg will, in the short term, perform much better than the Thrashers in the business department, the NHL just closed itself off to not only a large amount of people, but a large amount of corporate support and potential media exposure.
EDIT: Now, it could be that Fidel Astro was referring to the problem of "trouble franchises". That I disagree with on the basis of being a short sighted viewpoint, as well as the fact that relocation is absolutely no way to fix the problem in the first place.