I haven't done it yet. It's just entered into my mind. I'm pretty sure I am going to do it. I'm talking about a re-spec. Leiandra has been fire, or mostly fire since she first started gaining talent points back at level 10, years ago.
This is our second week of attempts on Al'ar (only the 2nd or 3rd night of attempts with our raiding schedule), and I know I'm completely useless as a pure fire mage. There's some great articles over at WowWiki that I've been checking out.
I guess the big thing with the arcane tree is the spell rotation. You want to use Arcane Blast as your main nuke, with Arcane Missiles threaded in there as well. Arcane Blast with the full 3 stacks of debuff is quite expensive (mana-wise), but then again, so is Arcane Missiles. You get a number of mana increasing and mana conserving talents, so hopefully that's the offset. I'll have to actually do the re-spec to fully understand the build, I'm sure. It's not the end of the world. And if I hate it, I can always re-spec again. It's only gold, right?