By light18pl at 2012-03-21 03:52:40
Taunt can actually be used to generate threat:
When you use taunt your threat will be bumped to whatever is required to be on the top. If you tount off from someone with 100k threat you will have 110k threat if you are in melee range, or 130k threat if you are further away. This also works if you are the top target, so you can use taunt off yourself for a nice 10%/30% threat boost.
Source: http://www.swtor.com/community/showthread.php?t=341126
In PvE, TOR's taunt seems to follow the same rules as the WoW version does:
It doesn't only temporarily attract the mob's attention, but brings your total aggro to the amount of the highest player on the mob's threat list.
So if your dps buddy suddenly jumped to 110k aggro (made up number) while you're still at 95k, taunting will bring you to 110k aggro and time to build more due to the "forces to attack for 6 seconds" effect.
I may be wrong, as this is based solely on subjective observation, but I have tanked for ~4 years in WoW and the feel of the mechanics is very similar.