next tier you'll be using
Evil Eye of Galakras +
Thok's Tail Tip. , the passive effects of the trinkets are by far the best for us. Haste isn't going to be bad next tier, it's just going to reach the point where it's actually not a benefit anymore (16-18k haste depending on the ilvl of your Thok's Tail Tip trinket) and when you've hit that haste sweet spot mastery value shoots through the roof but until that haste is still very strong.
To put it in another way, haste is still best until it's no longer a benefit to you.
Say I go with 21k haste without Thok's Tail Tip next tier, as soon as I get that trinket I can go down couple thousand haste because the passive gives so much haste AND mastery (and crit, not that anyone cares).