Scot McKnight, professor of New Testament at North Park, has a series of posts on "What is the Emerging Church?" Professor McKnight--whom I count as a friend--is more sympathetic to the Emerging Church than I am. However, I think he is one of the best writing today in terms of helping us to understand, on their own terms, exactly what this movement-mood-church is.
What is the Emerging Church?
What is the Emerging Church? Protest
What is the Emerging Church? Pro-Aplenty