This was the best thing that could have happened to Mo, to Kenny AND to the 10000 as an event.
10000: Because Jeilan & Co got to se that Mo's not unbeatable. I'm sure they took notice that going all out from a whole mile out (the one thing no-one's tried before) worked.
Kenny: He's back. We now have some wonderful duels to look forward to over the next five years, whether it be the Marathon, the half marathon again, or even him dropping down to the 10000 again (he does have his own track facility in Ethiopia to do PR for now so the incentive is there that way - remember, he did come to Pre to race Mo over the 10000 this spring but Mo backed down that time).
Mo: This will take a lot of pressure of him, especially from the Nike marketing division, who as of late not only has encuraged him to be all over the place (from the 1500 up to promises of a marathon next spring), including allowing him to promise PR stunts like that 600 meter race against Bolt (that never happened after Worlds, but was great intent-marketing for both).