chrtrplt:
There are a number of Americans now working as pilots for Emirates. There are also Americans in ground training roles as well as management. The number of pilots with a U.S. passport versus the number who were born and raised in America is different. There are defintely some dual nationals here. As there are a number who came from U.S. airlines in the last year but aren't " American " in the way you are asking.
Emirates did have a reluctance to hire Americans up until a year ago, but then they just couldn't ignore the number of applicants that they had from there. I think they have been very careful not to hire the loud " ugly American " type but that really goes for their selection of every pilot no matter where they are from. They try to hire people who will fit in to the multi-cultural environment and they do a very good job of it.
If you haven't been to Dubai or the Middle East it is a little difficult to describe how it is to live here. I compare it to a cross between Florida and California in terms of lifestyle. It is starting to have that endless strip mall feeling that so annoys me about Florida but there are lots of activities on the beach and in the desert that are comparable to those two states.
As to how Americans are treated here compared to other nationalities it is easy to just say we are Canadians, eh

Everybody likes Canadians

Seriously though, it hasn't been a problem as long as you are respectful of other people and their cultures.
As to your last question, it would all depend on your qualifications. They tend to be after guys who are qualified and current on modern narrow body equipment or better yet widebody.
Jim:
The reason for the increase in the number of Americans is quite easy actually. Things were so good in the States in the mid to late 90s that nobody really considered working overseas. Now that there are so many out of work that has changed.
BTW, what is the variety of the pilot group? Canadians? Brits? Aussies? Any other big groups?
South Africans, Kiwis, Swedish, UAE nationals. Did I miss any ?
Typhoonpilot