I'd like to say that App Studio is a game-changing addition to QuarkXPress. It isn't perfect (1.0 product releases never are), but it is stunning.
However, I too would like to have an HTML5 export option so that I could create content to be accessed by those without iPads, and for those who might not be so inclined to download and install an app before looking at content.
Given that Adobe has recently admitted that the development of Flash mobile is discontinued (and what that says about desktop Flash's long-term survival), and Adobe's public beta of Edge, for HTML5 animated content production, I really think it is time for Quark to build HTML5 into the output options - ideally both for Interactive and App Studio productions.