Freedom of Religion
All I know about the emergent church movement is what I've heard on the White Horse Inn and Issues, etc. Both programs are very critical of it, probably rightly so.
But they both missed the e-church appeal -- sadly, it's probably a false one -- of getting answers to doctrinal questions from an "unbiased" source. Here's what I mean. As I wrestle with a doctrine, let's say baptism for example, can I really expect a Lutheran pastor to genuinely explore beyond the standard Lutheran position? He'll explain all the relevant Scriptures from the Lutheran point of view and when I mention how others view the same passages, he'll say something like, "that's not how our church understands them." Or perhaps, he'll set up a strawman argument out of the others' position and then beat it senseless. Calvin sharply said, "There is not a more destructive plague than when men are so intoxicated by the scanty portion of knowledge which they possess, that they boldly reject everything that is contrary to their opinion." Rare is the person who has seriously tried to understand the different positions on a doctrine before arguing with others over the right way to believe.
Emergent churches, because much of their doctrine is "in process", seem like a more objective place to learn. But, for the same reason, they terrify me. Freedom of religion means complete freedom, even to believe lies, or not to believe at all.