The timing of this thread is really good. Someone over at SteelWarrior just did a Taunt Test (
their thread) and it seems Taunt is 10 hate in addition to putting you at the top of the list.
Someone makes the point in the thread that the value may not be static, but is around 10. So, as czaemon points out, it is still an insignificant amount of hate.
The most interesting part of the thread attempts to explain why a successful taunt may not get you aggro.
Apparently dfrnchman is right that something exists that we could call bonus hate. Bonus hate are hate points you get from things like initial (pull) aggro and from low health. Taunt does not appear to add these bonus hate points to your hate value on the mob's list - you only get the top-most base hate value plus 10.
As the test showed, when no fighting, etc, took place it actually took four successful taunts to take aggro from a person who pulled a mob. In reality a warrior is building hate from diciplines, weapon speed, and procs, so we can grab aggro quickly and might not notice this effect.
Edited, Sat Jun 25 19:33:53 2005 by JoltinJoe