You wont need it.

Unlike most MMOs WoW has got a high-powered piece of Spyware monitoring your computer, and accurate keystrokes is one of the things it pays attention to. Quite a few G15 users have been banned for having exactly 1.000 seconds between each of many pushes of a button (such as Arcane Explosion or Steady Shot), so obviously it works.

Oh and strictly speaking Warden (the spyware I mentioned) isn't spyware at all seeing as you gave them permission to run it on ur computer when you made your account. The effect of the program isn't unlike spyware, though.