Okay, so looking at people's hacks, and Vincent's comments on hacks and his development, I think I had a bit of a revelation (though it may be old news to everybody else). It kind of fits in with the notion that being the MC is "just a way to GM that may be old news to some people, but spelled out to those folks not familiar with it.
Basically, at first I was thinking "okay, how do I turn the AW classes into classes in X game, and how do I translate the core ideas like scarcity and barter into X world" and yadda yadda. Then I realized that AW is so great for hacking not because you need to change so little to make it work in other situations (although for some situations that's true - the Wild West, Iceland, some other situations come to mind where mostly cosmetic changes are all that's required) but rather because it is so easy to change extensively to your needs.
Again, this might be a "yeah, duh" notion, but to me I was struck that it was pretty cool. First off, everything the MC does is basically "how to do it your way" instructions that are all super portable. Other than maybe coming up with some different front categories and changing the "Barf Forth Apocalyptica" to "Barf Forth Your-game-ica", the whole Front and threats process works great for just about any setting, as it's more about how to approach thinking about providing adversity than it is a way to model post apocalyptic badness specifically.
Secondly, the basic set up of moves is like a framework for doing *anything* mechanically in the fiction. First, the mechanics of moves are dead simple: Roll + stat, with 10 being 'yeah you pretty much do that with no problem', 7-9 being 'you get it, but make a hard choice and/or get some adversity' and a miss being 'you get trouble and may or may not get what you wanted'. But the real kicker is to couple that with *very specific instructions* that point towards what characters are doing in this game in the form of lists of choices and the names for the moves and so forth.
The last major point about the system that strikes me as great for hacking is not exactly mechanical, but has mechanical implications. And that is that the rules constantly tell you to pay attention to the fiction and do what the fiction calls for, with the moves being a way to keep things exciting and unpredictable. Because of this, it's really easy to 'plug in' other rules that better reflect what kind of fiction you're going for (rules for spaceships, rules for craziness, rules for what you can fit in your backpack, whatevs).
Maybe AW is really a Vincent Move on providing a certain set of design tools, but misdirected and wrapped in Apocalyptica and with his bloody finger prints all over it, so we *think* it's actually just a game.
Does any of that make sense? Is it, in fact, too obvious to be worth commenting on?