Primeape, I definitely agree with~ n_n I remember it being brought up in this thread before; it evolving into something perhaps angrier, or maybe it's evo is a more calmed version of it (kind of like Slaking to Vigoroth)? Could be possible.
primeape evolution i would like to see, but hope they won't screw it up with something completly different that have no connection to its pre-evolution. i would like it to be even more angry.
by the way i don't think mankey is so calm to create a slaking evolution line.
(look at mankey abilities-vital spirit, defiant, anger point. such abilities show that he is not a calm pokemon).