Polls
<Poll of Iraqi exiles.
To be fair, I think this was an online poll, and you know what I think of them.
A protest referendum was held during the Iraq "election," where exiles cast their own votes against Saddam, but this does not automatically imply support for military action. The article has a lot of other good insights on the possible pitfalls of a post-Saddam Iraq.
I didn't find any formal polls on this subject, which probably reflects both a lack of media interest in the answer and the difficulty of assembling a random sample of Iraqi exiles.