It's interesting to me not because of it's application to vanilla AW. I'm not the type to get excited about a simple change in presentation.
It's interesting to me because of the possibilities for card-based hacks. In vanilla AW, you have a fairly limited but fairly static set of moves. You can choose to add one occasionally, but other than that your moves don't change much. A card-based system could facilitate a lot of different variations on that. For instance:
-The fun thing about CCGs is the number of interesting combinations of cards. You could have a great variety of moves, and part of the fun of character creation could be "building your deck". Cards facilitate a large number of moves, because of the way you can manipulate them individually, as opposed to having to deal with long lists of moves in a book somewhere.
-You could add a random element to it, by drawing a certain number of moves from a deck and choosing between those. This could be intended to model the difficulty in choosing the absolute best thing to do in a stressful situation: oftentimes you only think of the best option after the fact.
-You could make it easy and intuitive to lose moves somehow. If I told my Hocus that he didn't have hypnotize any more, until some necessary thing happened, we'd all find that hard to remember. If I can physically jank his card from him, it becomes much more tactile and significant.
We've mostly been talking about character moves, but it could also be interesting for custom threat moves. "There's another guard or something coming around the corner, let's see who it is. :Flips a card: Oh shit, it's one of the crazy mindfuckers, check out what you have to roll to go against him!"