Okay, so I found this today while leveling my paladin.
Basically, what you need is Dual Specc (I am Holy/Ret), right after I got out of a random instance (Was the healer) I forgot to change my specc and engaged a mob while in holy gear and specc.
While in holy specc I got the talent; Judgements of the Pure - Spell - World of Warcraft, this gives you 15% Melee and Haste speed for 60 seconds whenever you use a Judgement-ability while in Holy with this talent enabled. Now, the exploit/bug here is that obviously, like any buff it should go away once you change your specc, but it does'nt. So you can get 50-ish seconds of 15% Melee/Casting speed, now, I have yet to find usage for this exploit.
Sadly, you can't change your specc while in combat (so can't be used while on a raidboss or such). If you know anything useful this can be used for, tell me :)