Since Halo 4 is going to have sprint as a default ability unrelated to AA, I think they need to address the way melee works. It is not simply a matter of melee being too powerful (i think it is, but thats another story) its the fact that the way it interacts with shields, combined with sprinting makes for an un-fun balance.
If you have any shield at all, a Melee will simply remove all your shield. If you have no shield, it will kill you.
The problem here is, any bullet shot at someone before a melee that does not bring down the shield is wasted. This is incredibly silly when a player can simply sprint up to you and melee.
So now you have a situation where player A has shot player B 2 times, and Player B sprints up into melee range. Player A has no choice but to attempt to melee as well, since Player B’s melee will empty his shield yet another bullet from Player A will not.
So now player A and B have both melee’d, likely with player B hitting a bit first since he initiated.
Both players have empty shields. All of Player A’s initial shots are wasted.
Without sprint, one can simply back up and deplete a shield. Melee is something you do if a player gets close enough, or you turn a corner, or you sneak up on someone, it is not a viable tactic to run around in an attempt to just punch people.
With sprint? It is.
I am not saying melee needs a nerf, heck, a buff could solve the situation. If someone barely has any shields left, allow my melee to do more then just finish their shield, allow it to actually deal health. That way if we both melee each other, I have a health advantage and can get an easy body shot versus them needing a head shot.
The optimal solution would be a slight nerf. Have a melee deal half damage to shield, and kill without shield. That way if someone gets shot while running to melee, both players melee, the player who landed shots has a distinct advantage.
This is not even factoring in the “lunge” a melee gets to help close the distance on a player backing away.
Landing two punches on someone does not take much skill, especially with the sprint and lunge abilities. With spring as an armor ability at least you were sacrificing the ability to cloak, fly, armor lock etc to have this deadly melee. With sprint being universal, there is nothing really to balance it.