Hold on the flamethrowers please, its not what you think. I figured I'd try to compile a bit of info for an impromptu sticki (or at least a bumpable thread) with posts that answer the age old question.
So, here's where you're at. You've decided to take the fast track to 70 and have an enhancement spec. You're at, or just about to hit level 40 and now you ponder whether to keep your 2 hander or make the switch.
Here's what you need to do:
1) Read this, its the accepted guide to the DW/2H debate:
Elitist Jerks Shaman: Enhancement Guide - Two Handed Viability
2) Read these Alla posts on the (same) subject:
How much am I missing NOT DWing?
Whats the advantages of using a 2h weapon and DW
Regarding 2handed weapons
Can Shamans dual wield?
2h or dual wield for leveling?
2h or dual weild, that is the question
3) Post your question if it hasn't been covered in the extensive advice, conversations and debates above.
Keeping in mind that a generic 'Which is Better...' post made without any research may open you for a flaming.
Good luck and hope these links help.
Edited, Aug 14th 2008 6:43pm by OzoneSSX