I think part of the point that people have made is that Rupp rarely has gone earlier than 1200 or even 1000 to go, much like geb. At NCAA's he pounced on it with around 600 to go in both races and jogged in. The rest of the time made in those last 1000, 1200 & 1600 was made someone else, much like in Gebs race. In the 5K he hit a :54 from 600-200 and slowed up down the homestretch.
I'm not thinking that Rupp is going to medal, however if the race ends up being at 27:20 or slower pace at 8-9K i would expect rupp to still be in it and we have yet to see him close slower than 2:30 for the last 1K in a single race outdoors. Nobody knows exactly where Rupp is at, but we know he's stronger than last year at the olympics and with much more kick at the end. That tends to lead to good things.