Yeah, I was like "they can't ruin this moment that way" and, thankfully, they didn't. Then they fucked with us a second later! Had the timing down perfectly. Damnit, is Widmore one of the good guys or not? Actually, who are the goddamned good guys? They're making a halfway decent case for Locke at the moment.
I don't think that thinking about it in terms of goods and bad guys is the way to think about it. It's manipulators and manipulatees. It's about not being manipulated or used for someone else's agenda. On the island, as in real life, they don't what is really going on, they don't have the answers. The temptation is to cling to someone who claims that they do know the answers. Don't fall into that trap, it's just a manipulation tactic.
So, both Jacob and MiB are manipulators. They both have their own agenda and both use others to attempt to accomplish their agenda. They may have slightly varying methods.
MiB is more willing intervene directly and kill. Although, he still can be decent to those in his flock.
Jacob is less likely to intervene directly and less likely to intentionally kill. However, he still rips people out of their lives, which causes havoc in those lives and often kills bystanders.
In the end, MiB and Jacob are more similar to each other while their followers (aka the pawns) are more similar to each other.
The real moral, I'm guessing, is for the pawns from the different sides to band together and look after themselves rather than the interests of the higher powers. Pawns that devote their lives to their King/Queen simply risk wasting their lives for an agenda that is not their own. They may not even know the real agenda. They're just being used.
Mr Awe