But with all these new epic gems you ask yourself, "What do I put into my blue sockets now?!?!"
Arex has the answer!
Now, logic states you would want to for the most part fill your socket bonuses but now that you are able to get 23 spell power runed cardinal rubies your blue sockets become something you can ignore for the most part.
Now for your meta you will need 2 blue gems, this can be done with the 12 spell power / 10 spirit gems. Because of the improved moonkin talent this gem can basically be called "15 spell power and unnecessary mana regen."
12 spell power 10 spirit with the 30% conversion into spell power = 3 spell power. 12 + 3 = 15. 15 spell power + 7 sp socket bonus = 22 spell power Runed Cardinal Ruby - 23 spell power 15 spell power + 8 spell power bonus = 23 spell power = Runed Cardinal Ruby 23 spell power.
Most blue socket bonuses are spell power. So, the simple conversion is this.
If your socket bonus is not 8 spell power or more, you can ignore the blue socket and put in a runed cardinal ruby.
Once you breach the 8 spell power or greater mark in your blue socket bonus the
Quick Addendum. I understand that pending what your spirit may be, the 30% conversion its entirely possible that you might recieve one extra spell power from your 12 sp / 10 spirit gem. Due to this, you'll be required to do your own math. Simple math is as far as Arex is willing to go for you.
Some might say the 10 stat gems. Don't do it, the dps increase is not near as good as either the 23 sp or 12sp / 10 spirit.