After acquiring ITA Software, Google has access to a lot more information about flights and no longer have to send users to services like Expedia. Google can even provide information when you enter a vague query like [flights to Barcelona].
Here's the experimental flight OneBox, as spotted by Richard from SEO Gadget:
When you click "expand all non-stop routes to Barcelona", Google shows a very long list of cities. It's probably the biggest and most overwhelming Google OneBox. Maybe a drop-down would've been more useful.
After selecting one of the cities, Google sends you to a new search results page that shows a long list of flights.
It's nice to have all this information at your fingertips, but it's too overwhelming and these kinds of details aren't suited for an OneBox. Richard also noticed that "you get to data, with no call to action. I think this means most folks would be forced to repeat their search again on a flight provider."
Hopefully, Google will launch a Flight Search service that will also include the brilliant visualizations developed by ITA Software and the OneBox will just be a gateway to the new service.
Update: The feature is now available to everyone. "With the close of our ITA acquisition last month, we're eager to begin developing new flight search tools to make it easier for you to plan a trip. While this flight schedule feature does not currently use ITA's search technology, this is just a small step towards making richer travel information easier to find, and we hope to make finding flights online feel so easy, it'll feel like... well, a vacation," explains Google.
{ Thanks, Richard. }