Silly premise for this thread. Jager runs an awesome PR and is pumped about it, and still loses to Rupp who did not look at all like his best. How does this translate to Jager dominating Rupp in the future?
I think they are both great runners and I am certain that Rupp will at least PR again at 5k (and have a strong feeling he'll breakthrough and get the AR at some point). I am equally certain that we'll see Jager at 12:57 (if he takes enough attempts at the 5k), and potentially much faster (no idea what his limits might be). But let's not forget that despite all the hype about Jager's speed, Rupp is several seconds faster at 1500m.
As a fan I am glad to see a multitude of US guys capable of regularly producing a 13:05ish performances. Right now there is Lagat sub 13, Rupp at 13:01, Jager at 13:02, Lomong at 13:07, Derrick at 13:08, and True, Bumbalough, and Mead near 13:10 (I probably forgot some people near 13:10).
If the US is able to have about 8 sub 13:05 guys at the same time, the pressure to make the top 3 will likely ensure that the top 3 guys in any given year are between 12:55 and 13:00. That is really approximately the same level as Kenya or Ethiopia (maybe a fraction slower). In that scenario, in any given championship we should expect to have 3 guys in the final and one serious contender. I think the USA is only a few years away from this level. By the time last year's strong class of 1600/3200 guys enters their professional years, we should be seeing some medals in the 5k.
This glut of talent is already present in the 1500m, and though we don't have the top level times to show for it, we are seeing the medals. Between the 1500m and soon to be 5000m strength, I can't see how we aren't going to make inroads in the steeplechase. Obviously Jager is already doing so, but I see more sub 8:10s coming, perhaps in 2015 when people start thinking ahead about their chances to make an Olympic team. Imagine you can run 13:05 and are 8th on the US 5k list. You'd probably start looking at the steeple as an alternative.
These are just predictions, but it will be great to see what will come of the USA. So nice to see after suffering through the 90s...