tbh the reason haste falls behind, in 25 at least, is because of the huge proportion of healing that comes from lvl90 talents (and their DA procs). Haste is the stat that doesn't benefit this at all. It also offers no more healing per mana, which the other stats do. A minor point but worth mentioning. I suppose those points combined with both crit and mastery being very strong means haste becomes the least desirable stat.