As of the last ptr patch (when elem and enha dps was nerfed) the Conductivity talent was reduced from 3 seconds to 2 seconds.
Currently i am experiencing 2 issues with this newly nerfed talent:
1. Before this patch, regardless of your Haste, Conductivity was always adding exactly 3 seconds of duration. However now for my shaman it adds 1.41 seconds (instead of 2) because of (i assume) my Haste.
In other words it seems that the more Haste you have, the less time your spells will be adding to your Healing Rain - which is just awful, since the added duration of Conductivity seems to be reducing through Haste much faster than your spells/attacks are sped up by Haste.
2. As Enhancement 2 seconds is just not nearly enough to maintain a Healing Rain - at best i was able to slightly prolong it before it expired, but it was definitely not nearly as long lasting as it is when Elemental/Resto use Conductivity.
Combined with the above fact that Conductivity now weakens the more haste you have, while Stormstrike's/Earthshock's cooldown is unaffected by haste, makes this talent even weaker than it already is.
Personally i think that if the Conductivity for Enha is left at 2 seconds (plus reduction through haste) it will not be enough to compete with the other 2 talents of that tier.
Overall these two changes to Conductivity made it a pretty much worthless talent for Elem/Enha compared to AG and Rushing Streams.