Originally Posted by ShoGuL

Hm... to be fair levelling in this game is so laughably easy, I don't think it really matters what spec you have.

I have never been a huge fan of frost though - I have leveled two mages to 70 and going deep fire served me well both times, though for sure the talents have changed alot since then. Generally, you will have a hard time until around level 60 - you don't have alot of spell power and you can only kill one mob at a time at any efficiency, generally with fireball, fireball, frost nova, fireball - but once you hit level 60 and start getting gear from outlands, you will really start to feel über. Crits will start to almost one-shot mobs and you can easily take down several at a time using blast wave and firebreath.. I know for sure that I had no problem getting to 70 as one of the first blood elves on my second mage using a fire spec.

EDIT:
Levelling to 60 may be slightly easier now - back when I was levelling, spell power was extremely scarce pre-outlands