(As a side question) Has anyone here actually read McLaren's book or has everyone just read critiques about it?
(Back to topic) I think all too many times, the Reformed and Evangelical communities do everything they can to refute things that don't fit into their little box of what Christianity is supposed to look like. The emerging church is "unorthodox" compared to most "versions" of Christianity, and so everyone tries to refute it rather than trying to learn about it and grow from that knowledge.
This isn't to say that I support everything that they stand for. I think McLaren is wrong in some of his statements (I've actually read A Generous Orthodoxy). But at the same time, I think there is much that can be learned from what he has to say. There is much in this book (and possibly his other works as well) that can be edifying to the church, if we would all (myself included) simply heed the words of Jesus:
Do not judge, so that you won't be judged. For with the judgment you use, you will be judged, and with the measure you use, it will be measured to you. Why do you look at the speck in your brother's eye but don't notice the log in your own eye? (Matthew 7:1-3 HCSB)
Here is an article written by somebody within the emerging church in the UK. It is about the theology of the emerging church. Maybe reading something from inside will better help to form a definition rather than simply reading what people who don't like it think of it.
