In Kong 360, he attacks a T-Rex (or whatever they're called on Skull Island) while we happen to be the midst of the fight. It's never made clear if Kong is friend or foe until the very end, when he actively fends off one of the dinos from eating the tram.
I suspect that Reign of Kong will be similar, in that the vehicle is caught in the crossfire of a Kong battle and we're not quite sure if in the end he'll spare us. I suspect that he will given what we know, but it's definitely a change from the more sinister and villanious take in Kongfrontation.