Oct 5th 2010 8:15PM As a warrior tank of ~4 years, I can attest that this is generally not a good idea. Technically, yes... you may run into some tanks who enjoy the thought of applying an attack speed decrease in the first second or two. In your reply to Snuzzle you mention putting the debuff on 'the tank's target', which is probably fine. However, in your main post you mention potentially applying it to another target that has not reached the tank (and may not have threat on it).
After having done a little bit of tanking in the beta, I can say that AoE tanking is not nearly as powerful as it used to be. It's very easy for someone to pull aggro on a mob that's not being focused on, especially in the first few seconds of a pull. Consider a situation in which you earth shock something the tank hasn't targetted, maybe it crits and out-threats the thunderclap (which has been SERIOUSLY nerfed, and applies the debuff anyway). That mob may now be focused on you, so the tank has to switch targets and taunt (which may be resisted), or charge/intervene. This throws off positioning and disrupts the tank's initial threat rotation, which leads to your DPS overdoing it on the primary target, then they pull aggro.... etc.
Not saying this will happen every time, but it's a very distinct possibility to instill chaos into an otherwise potentially smooth pull. Given the fact that CC is required now, and properly orchestrating pulls is going to be necessary, I'd have to say that unless your tank is expecting it and properly compensates his threat on your earth shock target, to avoid this entirely.
Apr 22nd 2010 1:09PM Also, you can right-click their name in the chat window, or targetting portrait, and select 'whisper'.