While the dual wielding goodness/badness that is Titan's Grip continues today, Heroic Leap was removed mid-beta with Warriors everywhere screaming and crying. Yours truly shed a tear. I loved leveling through the Howling Fjord and Dragonblight with Heroic Leap at my side. One press of a button and bam – I'd be raining down upon my enemies with my plate shining and dual two-handers blaring.
Its demise has always been speculated upon. Many thought that the skill just provided one too many ways for a warrior to quickly move about the world. Others thought that it was due to it being too over powered in PvP. Still others thought it had to do with exploitation of the terrain.
It turns out that those folks who thought that exploiting the terrain was the reason for its demise were correct. Ghostcrawler weighed in on Heroic Leap's removal and gave this very reason.
When you think about heroic leap from a game stand point, it is an ability which avoids the majority of terrain, and thus limits on the player's movements, to get to a given mob. Is there a stump between you and that nasty spider you want to kill? Heroic Leap and wham-bam-thank-you-ma'am, you're over the stump and standing on top of the spider beating the living daylights out of it.
It's this nature of placing the player at the mob while avoiding the majority of terrain paths that caused Heroic Leap's demise. Players could (and did) exploit this. Thus the ability had to go.
Ghostcrawler answered a criticism that the Death Knight's Death Grip did the same thing. He points out that with Death Grip you can assume the player is in legal terrain and pulling the mob to them. You can't reverse Death Grip and go to the mob. Thus if the mob is somehow in illegal terrain, it's not an issue. With Heroic Leap it would be.
Ghostcrawler does make an interesting revelation. He mentions that they had thought about making Heroic Leap a Blink or Disengage like ability. In the end they decided against it. But I have to believe and have hope that one day Heroic Leap might find itself back in the game with mechanics like Blink.
I can hope, right?