One of Blizzard's favorite encounter mechanics is the pool of goo or fire or other AOE element on the floor where you are standing.  Should you consider to stand in said spot, you will take damage, stress out your healers, and possibly die, putting THAT GUY in your raid over the edge where he will rip you a new one over vent (or in whisper if he's nice.)  Blizzard loves this mechanic so much that they threw it into their holiday encounter for Love is in the Air.  In order to make it even more "fun," they threw in twice the goo and pretty colors to go along with it.  I have to say it's a creative way to make people more mobile during a fight, but as a mage that has to ramp up damage to do decent numbers, it's a bit irritating to have to jump around all the time.

So what are the encounters that burn me up all the time (sometimes literally)?

Lady Deathwhisper:  Being a mage means that I'm on sheep duty (or Black Cat duty in my case) for the first phase of this fight.  That means my positioning is somewhat important if I want to catch the next wave of adds before my new friend decides to eat the rest of the raid.  Unfortunately, poly isn't an instant cast so naturally with my Rotten Luck (hehe) Death and Decay lands right where I am in the middle of my cast.  This is more or less random, so it doesn't happen all the time, so naturally this is easily remedied most of the time.  Move out and recast or POM repoly.

Lord Jarraxus:  I love spellsteal.  It's by far the best version of dispell/purge ever.  Some of the buffs you can get are kind of useless, but most of them are pretty darn cool.  So ripping Nether Power off this guy thrills me, especially when I'm the only mage.  You can get 2-3 stacks off him if you spam it fast enough, more in 25 if there aren't any shamans wasting it with Purge.  Naturally the damage goes to my head; I get all excited and then when an Infernal comes up and starts Hellfiring my boots, I have to move quick.  I get 30 seconds to move and start ramping up Arcane Blast again before pew-pewing with my Missles.  Generally you don't have to get too far, so this isn't so bad.

Rotface:  As far as I'm concerned, the king of the AOE damage hurts.  Ooze flood and Slime Spray, thankfully, don't happen at the same time, but this fight is so movement intensive, it's frustrating.  I've only seen this guy a handfull of times, so I can't say I've figured this guy out for myself yet.  We have a special kind of hatred for each other and he's holding my trinket hostage.

Professor Putricide:  We won't even go here.  This guy makes Rotface look like a newb.

And there are so many more, and no doubt more to come because Blizzard has a special place for targetted AOE and mobile fights.  So what's the best way to avoid this stuff?  While it seems like a good idea to pop your defensive cooldowns, as a mage that means Iceblock and Invisibility, it's not your best option.  Sure sometimes its a bit far to run and you may not make it, but please don't forget about Blink.  It's instant cast and gets you on your way as long as you're facing the right direction.  Sure it gives you a global and makes you wait a minute to start up again, but your healers will love you more if you move.  Mana shield is less than favorable option because it actually drains your mana and Ice Barrier is limited to Frost mages (who don't really exist in raiding.)  Blink is your friend.  Learn to love it.

The point is, until they make Mage tanks and we start stacking stamina, do your healers a favor and get out of the fire.  Chances are they're busy trying to keep someone who has no idea what's going on from dying, or you know... the tank who's the only thing between you and the boss on the threat meter.