Seeing how Kyogre and Groudon have something similar to Mega-Evolution(wasn't it call primitive/primal evolution or something like that?), Rayquaza without a doubt will be having one.
Minun and Plusle... well like said above, they majorly rebound about working together, and only one pokemon can mega-evolve per battle, but it wouldn't be surprising to see them have a mega-evolution, so that they can be worth anything, when fighting alone.
Jinx, well I don't know what to think about that one.
COMG guide to points: 1 point = Raging. 2 points = Beasting. 3 points = Tearing it up. 4 points = Berzerk. 7 points = Rampage. 12 points = Burst. 15 points = god mode. 20+ points = DIVIDING BY ZERO!!! 40+ points = Youkai (originally Pokemon).
-1 = Negabeasting. -5= NegaRampage. -10 = NegaBurst
