Now before you think, RoosterTeeth already did this! Yes, they did a video of grifball in minecraft, but not proper grifball. Multiplayer servers/plugins and more expertise than they have allows for some pretty amazing things to be possible, and now grifball minigames in minecraft are in a multiplayer server owned by ZexyZek. I'm not much of a fan of minecraft anymore, but I guess it's pretty cool to see more the fun "action sack" gametypes that are/have been specific to halo in other games.
Server ID: McGrifball.com