Ok, I was in WSG and I charged an enemy...he was running at the same time and I actually think I had a much longer Charge.
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So...here's what you can do to get this to happen/confirm it.
(This is to totally maximize it...)
1) Goto Outlands
2) Get a friend or someone with a Flying Mount to help you.
3) Go somewhere perhaps with a lot of empty space (if possible)
4) Duel this person (or you can just get an enemy to help you if you can talk to them irl or something...)
5) Ask him to mount up on his (fastest) flying mount.
6) Charge him and tell him to start running with his mount when you start to charge.
7) If it works, you should be Charging your friend for quite a while. (Ask him to start flying on his mount. If you still Charge then this is also a Fly without a Flying Mount Exploit hehe)
Simply put... just ask a friend to run and then charge him when he's running...
*I'm not like 100 percent on this or anything...but it worked for me on accident...*
*Post here if you totally confirm it *