Cataclysm gemming

[Abominatus]

I've been looking at the changes (such as they are this far) to the gemming system in Cataclysm and trying to get a feel for how we might end up picking our gems. (I'm viewing this from a warlock perspective of course).

Obviously, at time of writing, there are 2 problems. Firstly, we don't really know what the relative values for our various ratings might be. Secondly, gems are still very much a work in progress on the beta, as can be seen from even a cursory examination of the Wowhead Cata database.

However, the following points seem reasonably clear:

• Red gems are going to be intellect for warlocks. There seems no reason why that wouldn't remain our premier stat (taking over from SP) and it's highly likely that we'll want all our gems to retain a red component even when matching for socket bonuses
• Yellow is going to be a choice between crit, haste and mastery. Your choice will vary based on what the maths says is the best stat
• Blue is weird. At this point, the only stats in blue are stamina, spell pen, spirit and hit rating. We no longer use spirit, spell pen has no use in PvE, stamina seems extremely suboptimal to gem even given the increased desirability of survival stats in Cata and Hit is a capped stat

If it goes live in that distribution, I would expect that we will be gemming for hit in blue (where neccessary for socket bonuses and meta requirements) and reforging gear with hit  to maintain the cap. This seems lame to me. Especially given that there is a fundamentally false choice presented in yellow in that although there are 3 interesting stats, it is inevitable that one or another will be supreme and therefore will be gemmed for exclusively, just as is the case with haste now. You can probably make 2 stats close enough in value for a given class that the choice between them is interesting, but doing that for 3 seems far too difficult to manage successfully.

If I were to suggest an alternative, it would be to make Mastery rating a blue stat. This has all kinds of interesting implications. Firstly, once you start hitting the new hit cap in Cata, you have the option to regem for mastery, making a desirable exchange in the process and making reforging less a case of "always reforge to remove hit". Secondly, it creates an interesting dynamic for both tanks and healers, whereby they need to trade off mana regen/health pool for mastery rating, which intrinsically improves their performance in a different way. Balanced correctly, this becomes an "interesting choice" instead of the existing paradigm for blue gems in which healers always gem mana regen, tanks always gem stamina and casters always gem spirit (hit rating in Cata).

Ultimately, hit rating going from yellow to blue is a good move, and is certainly beneficial to physical melee DPS classes (what the hell do you gem for in Wrath in a blue socket, stamina? That must suck balls). But the removal of spirit as a viable DPS caster stat means that blue retains only 1 viable option for casters. That leaves us with 1 red gem choice, 1 orange gem choice and 1 purple gem choice, which really isn't much of a change from Wrath.

Any thoughts from other class perspectives?