You may recall this snippet from my previous article, Living Seed, Replenish, and Gift of the Earthmother:
Unlike other talents that affect casting speed, the reductions from spell haste and GotEM are additive; both values are calculated off a 1.5 second global cooldown and are not applied in any particular order. This means it actually scales better than it would otherwise and, contrary to popular belief, does not scale inversely with haste. Nonetheless, plan to drop one or more points out of this talent as your haste increases.
With the release of Patch 3.08, this is no longer the case. Gift of the Earthmother has been changed so that it’s applied the same way other self-hasting talents are, representing a considerable nerf to its effectiveness. As a point of reference, you now need 655 haste rating (19.98%) to reach the same 1.0 sec GCD you could formerly reach with only 505 haste rating, assuming 5/5 Gift of the Earthmother.
We can adapt the formula provided by Zoltair of Korialstrasz (US) via Elitist Jerks to solve for the amount of haste needed to reach a 1.0 sec GCD at different points in GotEM:
Haste from Gear = (1.5 * (1 – GotEM%) / ((1 + WoAT%) * (1 + Aura%) * (1 + CF%))) – 1
Thanks to readers Zoltiar and Trellan of Ravencrest for the heads up on this change and to Zoltair of Korialstrasz (US) for the math!