@poissondemer: Honestly, Frost is perfectly fine and acceptable as a spec for Heroics, and don't let anyone tell you otherwise. Unless you've got a rogue in the group you will probably top meters, and there are certain Heroics where Frost really shines. (Hell, I am pretty much full time Arcane but I still switch to my AoE Frost spec for the Tribunal of Ages.) Though I would still recommend Arcane over it at least as a fresh 80, because your #1 priority as a fresh 80 mage is to reach hit cap, and that is way easier to do as Arcane.

I will say this though. I was a diehard meter-topping Frost mage from the beginning of my WoW career, all through BC and only switched to Arcane after Wrath hit and it was obvious Frost was no longer competitive in a raid setting. I will tell you that I am a hundred times a better mage since switching to Arcane. Point blank. Why? The lack of safety net and oh shiz buttons as compared to Frost. I have far greater situational awareness simply because I can't rely on having a big frosty barrier to protect me if I eff up somehow, like accidentally stand in stuff. I have to watch my threat like a hawk because I can't rely on a short Ice Block CD to bail me out. It forced me to really use the entirety of my toolkit. I could go on, but really, changing from Frost just plain made me a better, smarter player.

One last thing: the speshul snowflake attitude is a bit silly. I find that far too many people with this attitude of "eff the cookie cutter specs, I'mma have fun MY way!" really fail to understand the mechanics of their class. Cookie cutter specs become standard for a reason, they are generally the best way to do things and there is little point in trying to re-invent the wheel. By all means, play what you love, but just like every freshman composition professor will tell you, learn and know the rules before you decide which ones you're going to bend or throw out. Or else you'll be the Arcane mage I was in a ToC25 pug with who had no idea why I was destroying him on the meters, and a look of his spec revealed no points in Incanter's Absorption (a debatable talent, but basically free dps given the prevalence of Disc priests bubble spamming these days), and none in Incineration (+crit to our main nuke, no earthly reason not to take it).