I don't like "evacuee." It's a painful back-formation, a nouning of a verb. I understand that some people believe that "refugee" has negative connotations, but the word accurately describes people who have fled from their homes seeking refuge.
I'm on the losing end of this, though.
The overwhelming human toll of Katrina has made members of the news media particularly sensitive to their traditional role of defending the underdog. Thus, they were quick to change when objections surfaced. The wire services are using "evacuee" almost exclusively now.
I don't change the word to "refugee," but, as I said, I don't like it. Words only have the power we choose to give them.