There are several breakpoints in the hastelevels in which, if you can't get to the next one it's best to swap excessive Haste to Mastery.
These are typically dependant on the buffs you expect to have plus racials.
For instance. Do you Have DI? Are you a goblin? DO you spec in to Darkness with 1, 2,3 or even no talentpoint (it's rare but it happens.)
There is a list compiled (can't seem to find it now but sure someone else will do the honours) for which breakpoint you should go depending on race/buffs.
Regardless of that there is a fixed breakpoint of 3202 Hasterating that increases the damage from IDP that does not scale based upon aforementioned variables.
Judging by your armoury you're currently 160 Hasterating away from that breakpoint so you could opt to reforge excessive Haste to Mastery.
Okies, based on that information your lower breakpoint would be the one where DP gains it's second tick being 2284 Haste.
The next breakpoint is the 3202 I mentioned. If by acquiring new gear you can reach that number I'd suggest to reforge in that direction. For now Reforge downward.
Changing to Draenei will give you a 101 extra rating that you don't need to invest in Hit due to Heroic Presence.
I'd suggest to put this in haste as well, leaving you only 59 Hasterating to acquire.
If needs be, regarding reforging around these breakpoints, I'd suggest you use ReforgeLite.
It lets you insert custom numbers to work around. One being Hitcap. Second being your haste breakpoint you want to attain.
As has been talked about frequently, the haste breakpoint which is critical right now is 30% raid buffed. A few top priests have geared for higher haste, but generally we find the most success with 30% haste/high mastery builds on most fights.
Do not gem for haste. Do not take 50 haste over 65 mastery unless you have terrible gear and cannot reach 30% haste. Intellect is always your top priority by a huge amount.
All of the above really only applies if you have the shadow 4 piece set and are using the 4 piece rotation.
If you aren't, I would recommend just gearing for haste>mastery>crit regardless of any plateau.
---------- Post added 2012-04-17 at 09:37 AM ----------
Originally Posted by fuds
would gemming a tad into haste be worth while?
im significantly over the 6k int everyone seems to be going on about.
The 6k intellect point is not anything to be concerned about. Intellect is still your best stat at that point. It always will be.