This is nonsense. As the second-poster Reed has shown, it is a very rare thing indeed for any world championship 10ks to go under 27 minutes--2009 was an anomaly when, if I recall, Tadese hammered it like crazy, and Bekele and Tadese pushed into crazy territory (relative to world championships). I think, also, the only reason, like Reed said, that world championship 10ks were every close to 27 flat owed directly or indirectly to the presence of the 5k/10k/long distance GOAT in the race--a strong Bekele.
And I think that before Bekele and Haile arrived on the scene, such fast 10k track championship performances were totally unheard of.
While there is a good chance Gebremeskel, in a very well-paced race, has a PB in him of sub 26:50, nothing close to that is going to happen in a non-paced championship race.
The original poster's suggestion is way over exaggerated, although I agree with the general idea: There might be a possibility that the Ethiopians and Kenyans together will push the pace the whole race toward low 27 minute territory, maybe ~27:10. Absolutely no way, in my opinion, will the final winning time be 27 flat or under.
In that case, Rupp's chances will still be in question--he will need to have the fitness and the motivation to summon 27 flat and sub 27 strength, just to be in contention. And then he will need to be able to finish hard, perhaps in a progressive kick from 400m-100m, perhaps in a 1200-1600m last grind. Rupp is a phenomenal athlete as his 10k PB and Olympics silver medal prove, and has incredible potential as his middle-distance achievements indicate--but that doesn't mean he will perform come this weekend.
I also think things are still uncertain enough to be interesting as far as Mo Farah is concerned. I'll definitely be tuning in for the entire race. If this possibility is realized and the pace is pushed honestly the whole way, with the added possibility of a last grind and/or final kick, Mo Farah will have to rise to the occasion and summon his truest best colors and performance. That will be riveting, and it could be a beautiful thing. I hope to see the Ethiopians and Kenyans pushing it, and Mo Farah, Gebremeskel, Abera Kuma, and Rupp all in contention. Jeilan and Merga could be there, too--all those athletes have incredible talent and ability, but whether we see them rise to the occasion and display it--which would make for maybe one of the most exciting 10k championship races ever--is another question.