"So the 10000m team will be Rupp, Sam, and a toss-up between True and Derrick?"
No, not True. He has made his intentions clear he "does not like the 10k." His own words, stated in his Heusden-Zolder post-race video last month. With the Oly Trials having a 5k semi, look for him to not even be entered in the 10k which comes first.
However, Chelanga does add considerable intrigue to the 10k, especially if can stay injury free for the next 10 months and arrive at the Trials in good shape. Chelanga, Rupp, Derrick, Mead, Estrada (presuming he's not on the marathon team by then) would be the 5 favorites for the 3 spots with Kipchirchir, Rono, Vail (again, presuming not on the marathon team) pretty close behind.
At this point, only Estrada & Mead (and True) have the 28:00 Oly Q time within the Q window which began this year. Rupp & Kipchirchir could get it in Beijing if the pace allows and they are on. Chelanga & Derrick will have to wait until next year's Payton Jordan or Pre or the Trials itself.