I find that Google's innovation for almost every one of their products is in saying "we have oodles of data, how can we display it effectively"? They have done well at collecting and quickly accessing large amounts of data, linking loosely coupled sets, and in some cases, adding meaning (image searches understand the concept of "bright" or "dim", for example).
But I rarely see them taking the data they have and merging it in a way to create new meaning or value. Hipmunk, beyond co-opting a gantt chart, did this with their "agony" score. Google not only didn't try here, they didn't try for local search either, and just acquired Zagat for their score (and brand name and loyal following, etc.). And many startups offer meaning above and beyond that combined in the data: through their experience, their ability to merge context from being subject matter experts, or just their flexibility to experiment without a spotlight on them. Google tends to stop short of any of these.
So, yes, it's no Hipmunk: it's a typically well done Google product taking hairy data, merging it up, and displaying it well. Doing more than that, however, is left to the rest of the world.
(Though, one wonders why ITA didn't do some of these things before when they first created this better way of looking at flights a few years ago...)