Firstly, I know there's a post on this for duels, but i've noticed this becoming more frequently possible in other areas except for Arenas (Not sure why). Simply put, if you start 'hopping' in a diagnol direction, different from the path you were moving in when a warrior just hits their charge, you'll generally not be hit if you're quick enough.
(Tested with 80 Holy Priest VS 80 Prot Warrior)
Another nifty feature is how Warriors will sometimes reflect spells, it's funny to see Death Grip land and the warrior as well as DK go swinging in two crazy directions. LOL
(Watched this happen on the bridge in AV, they both died from fall damage)
If anyone has any more statistical data on this it'd be much appreciated in a PM or such, or reasons as to why these events happen.
~ NOT GUARENTEED TO WORK 100% OF THE TIME, BUT WILL WORK OFTEN WITH SKILLED PLAYERS ~