I haven't found too many of these yet, but I will update as I find more.
With a G15 keyboard, you can make a simple macro which spam a key(s) at any desired repeat speed. I won't get into "how" as this is not a tutorial on G15 macros.
1) So, for example, everyone knows the exploit: How to get BOTH tabard of summer skies/flames and both ilidari at once! , using the G15 extremely fast repeating macros can make this process way easier first of all.
2) On the quest: Mission: The Abyssal Shelf, you can fire off around 5-6 bombs when you set your repeat delay to around 0.05 second, instead of the normal one bomb.
3) On the quest: Blightbeasts be Damned!, you can set the two flying mount abilities to spam again and fire off around the same 5-6 fireballs, instead of one.
So my question is: Has anyone else noticed this glitch yet, and where in the game have you use it so far? There are ways to do this without a G15 by changing keybinds for your mousewheel, but G15 can get more specific.