Here's some more good news today for mages. On top of Hypothermia going back from 45s to 30s, Kalgan has stopped by the mage forums to promise some additional buffs in person. These probably won't make it into 2.3, but he says they'll go in "in the near future." My guess is that translates to 2.3.X or 2.4. It looks like Blizz is basically in a "buff" swing recently, which fits in with their general design philosophy -- start underpowered, and then build the classes up as necessary. Buffs make far fewer people angry than nerfs do.
What are these buffs, you ask? Trainable Ice Block, and "to-be-finalized improvements to mana issues in longer fights" (source). We've been seeing more and more skills moved to trainable as the game has matured, from Evocate to Holy Fire to Improved Sap. Ice Block mades good sense to add to that list. Kalgan's reasoning is that IB is something they want to be able to design PvE encounters around all mages having, and that it helps open up the range of viable specs for PvP. As far as the "mana issues" improvements, it's hard to comment too much on that without any details, but efficiency is good. Any speculation on what they're going to do there?
Oh, and in a later post, Kalgan lets slip that mana gems are also slated to be buffed. Let that be a sort of after-dinner mint of buffage.