Taunt drastically increases your Threat rating for NPCs - 1,000 * TauntDurationRemaining, to be exact (this also means the Tanker using Taunt every 30s will likely lose aggro to the Tanker spamming Taunt as fast as possible). As far as we know, no other elements of Threat that we know of (attacking, proximity, etc.) have such a coefficient. NPCs use a list of targets sorted by Threat to help the AI decide who to attack.
Of course, even if you've got the highest Threat in the room, if the enemy is confused, he can't attack you.
I'm not entirely certain how that interaction works in PvP, since Taunt works entirely differently in PvP.
http://www.fimfiction.net/story/36641/My-Little-Exalt
Ok, what about the confused part?
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AFAIK Confusion flips the "Ally" and "Enemy" for the confused entity, for the duration of the confuse. Taunting a confused enemy will have zero impact while they are confused, but could result in the taunter being at the top of their Threat list when the confuse wears off, which will result in them changing their target to the Taunter.
Since Taunt runs on the target entity, the duration continues to run during their confusion.
The wisdom of Shadowe: Ghostraptor: The Shadowe is wise ...; FFM: Shadowe is no longer wise.
; Techbot_Alpha: Also, what Shadowe said. It seems he is still somewhat wise 
; Bull Throttle: Shadowe was unwise in this instance...; Rock_Powerfist: in this instance Shadowe is wise.; Techbot_Alpha: Shadowe is very wise *nods*; Zortel: *Quotable line about Shadowe being wise goes here.* Interesting - I just never thought about it until the day I made a new tanker. Thanks.
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What happens on the technical side if you taunt a confused enemy?
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