Korir's spot in the Olympics is looking good, but still far from gauranteed. He could run a fast marathon in a few months to gaurantee it, but that might hurt his performance at the olympics.
An idea, what if Korir's sponsor offered a cash bonus to the first US marathoner, who was not in the top 3 at the trials, to run 2:08:10 or faster before May 5th. If no one runs the qualifying time by May 5th, but a non-top 3 finisher at the trials passes Korir on the road to Paris list, the prize goes to the highest ranked American (out of the non-top 3 finishers at the trials) on the road to paris list.
Right now there is little incentive for US marathon runners to gaurantee we get a third spot (except for Korir). It is definitely in Korir's interest to give fellow Americans who missed out a push to go get him that third spot.