I guess, I mean it could probably work with a few major modifications to what we think of as "sandbox" games. Bringing in more of the team element, less of the solo stuff.
It'd be nice if it were more mission-focused though, instead of killing 45 minutes flying around and ignoring everything else, y'know? That doesn't really seem to fit with the series, aimless exploring for the hell of it, a la GTA. It could probably cut out all of the inter-mission stuff, eliminate all the stuff between and just focus on the task at hand.