The current design has been reconsidered, so we're planning to revert gems that now require more blue than red gems back to their original requirements. Such a change can't be accomplished via a hotfix though, so we'll have to wait to revert these in a future patch.I'm glad that they are making the chance but couldn't they have decided this before I spent 700g regemming for raid.
New Cata Gemming Strategy:
For the most part, our Cata gemming strategy will be the same as it was in WotLK with a few possible caveats.
Meta Socket: [Chaotic Shadowspirit Diamond]
Red Socket: [Brilliant Inferno Ruby]
Yellow Socket: [Reckless Ember Topaz] with Int Socket bonus. [Brilliant Inferno Ruby] with secondary stat socket bonus. The thing to remember here is that secondary stats are worth no where near as much as Int at least in early Cata raiding. An additional 20 Int is likely better then 30 of any secondary stat. In fact, I'm not a 100% sure that a Reckless gem is the right choice when the socket bonus is Int, but I'll need to see some more math before I make that change.
Blue Socket: At least 2 [Purified Demonseye], but maybe [Brilliant Inferno Ruby]
if the socket bonus particularly bad and you don't need the hit.