You've probably already read Peter's initial reaction to the trade, and if not, then do so. Having had the day to think it over, here's what I'll say:
The Sharks "won" the trade, in that they got the best player out of it, and have created a top-line that is going to absolutely dominate next season. Though the Senators didn't get a fantastic return on Heatley, it could have been a lot worse: they could've ended up with Dustin Penner. (Yes, I think that this deal is better than the nixed Edmonton deal)
That being said, however, there are many positives that come from this. First of all, the team has spread out the cap space among the forwards, which is extremely important in order to be flexible under the cap in the next few years. Though Cheechoo's $3M cap hit is far higher than he deserves, it's only there for two seasons, a much shorter length of time than Dany Heatley's - or Dustin Penner's, for that matter. Speaking of Cheechoo, the man's hometown of Moose Factory must be thrilled to have their favourite son back in his home province. Unfortunately, all the road-trips in the world won't save the Senators' current ticket sales woes: even if every single person in Moose Factory came to the same Ottawa Senators game, they would only fill up approximately an eighth of Scotiabank Place. There's also that second round pick that might, you know, devastate the Leafs' squad in a rookie tournament next year.
Another positive is that the Sens find themselves with a deeper pool of forward talent, which should help the team avoid the label of being a one-line team. Michalek and Cheechoo join the likes of Jason Spezza, Daniel Alfredsson, Alex Kovalev, Mike Fisher, and Nick Foligno, six of whom should fill out the team's top-six forwards. In fact, TSN's Scott Cullen seems to think that our forward lines might even be better after this deal.
Finally, there's also the things that stats ignore. Though Dany Heatley is a great scorer, he was a frequently lazy one-dimensional player that would have been a huge distraction for the club. Michalek brings with him a very strong two-way game, Cheechoo has a well-documented work ethic, and neither of them are going to damage the locker room in the ways that Heatley likely would have.
Sometimes trades go down to shake up a roster, or add to an area where your team is lacking. Other times, trades go down simply because the team is forced into it. This is a case of the latter, and considering the Senators had no choice but to trade Dany, they could have done worse. I'm not satisfied with the return, but I don't think I ever would have been.