Fixed too soon. Fun not allowed.
For 3 sec after casting Heroic Leap, you may cast the spell a second time without regard for its cooldown.
Increases the damage done by your Heroic Leap by 200%.
Barbarian - Spell - World of Warcraft
The above is the new pvp talent available to warriors who enter PvP, be it through War Mode or battlegrounds and arenas. As it says, you can jump a second time directly after landing, and it's quite useful for mobility. However, the second jump can proc off of itself! I figured this out by accident, but here's how you replicate it;
1. Cast Heroic Leap with Barbarian active, Barbarian lights up Heroic Leap.
2. Cast Heroic Leap about 2.5 - 2.75 seconds later, Heroic Leap loses the light up from Barbarian mid-jump.
3. Upon landing, Heroic Leap will light up from Barbarian being triggered.
4. Repeat steps 1-3 as much as you can.
Basically, the proc disables in the middle of your jump before you land, making the game think you cast a normal Heroic Leap instead of a Barbarian proc when you finally land. Best I've managed is seven before messing up, but if you can time this properly, there's nothing stopping you from jumping around forever. At least until Blizzard fixes this, of course.