Two years ago Google said they would never do exactly what they are doing now. Although this is only currently being rolled out to 3% of Google users, I believe this is likely just a test to see the banner’s impact on conversion rates. If successful I imagine that the 3% number will increase dramatically and more than Southwest will take part.
I personally find the most interesting part of this article is the fact that the top organic result will now be pushed down to the bottom 13% of the screen. What impact will this have on SEO? Does it make it even more important because it is now so much more competitive to be on the first page, or will it become less important due to such limited space.