Eh, Kara has also been a media darling for the past few years. She is on the most high-profile team in our sport, has graced many magazine covers, and tends to run very well in big races. She's like Ryan Hall in that even though they may not be lighting the world on fire recently, they are very popular and have earned a lot of the attention over time. Also, an elite athlete returning from pregnancy and competing is always an interesting story to which women and the everyday jogger can relate.
I agree that the Nike marketing machine is massive, but you can't expect one weekend where Davila runs better than Kara to suddenly garner her loads more attention. The trouble with elite running and fans is that it is hard to keep up with the athletes year to year when they only race two or three widely covered races, and are experiencing ups and downs in the form of injury and illness all along the way. They need people they can follow, and the apparel companies know that. When Nike or Asics is given someone like Ryan Hall or Kara Goucher or in New Balance's more recent case Maggie Vessey, that has proven to perform at a high level while being clearly visible at big meets/races and fits the all-american image... they will throw a lot of money behind that athlete, putting them front and center. Brooks did the same thing with Brian Sell. He was the "blue-collar" runner who busted his ass to get on the squad and everyone ate that story up. Do you think that Vessey will be getting less exposure from NB just because she bombs in a couple of races (if she does)? No, they will keep her out front in their marketing campaigns for at least the season.
Let Davila show up the big dogs like Shalane and Kara this year in a major marathon, and then let's see if Brooks is willing to put a ton of money behind her image and continually rising performance pedigree. I hope it comes to pass, but again, the marketing folks are picky, and it is just as likely they will choose someone else in their development stable who they feel will bring in the attention of their audience, which, surprise surprise, isn't all elite athletes.