Actually, I can see it hurting fighing any mobs that can charge/intercept in PvE or warriors in PvP (also, boar pets).

It's a lot of fun if you can rotate it out (i.e. multiboxers) but my opinion is that Thunderstorm and Disperssion (Shadow Priest 51 point talent) are almost completely useless outside of PvP. Even PvP doesn't seem like that much use.