Before anyone mentions it - Yes this is common knowledge, however not everyone is aware of this and I didn't find anything when searching for "charge, feral charge, arena" about this so I guess it doesn't hurt if I post it..right? And yes it has worked since time began, but since I don't see it posted or the post was deleted here's how it's done:
Only works for Feral Charge(cat, obviously because it's more of LEAP than a CHARGE), so only a Druid exploit
1. Go on the 1st floor of the Blade's Edge / Dalaran arena
2. Find a target near the edge of the 2nd floor
3. Shift to Cat Form
4. Cast Feral Charge - Cat
5. PROFIT
This works great against ele shammies who tend to push you down or warlocks who demo circle up.
P.S. Yes it's more of a Trick than an exploit, but I'm 100% sure Blizz didn't intend for this to be possible or all other Charges (Warrior charge/intercept // Bear Form Charge etc.) would be able to do the same (which they can't atm).