The Resurgence has a short and interesting post on the multi-site church movement.  He more or less comes out for it.

What is most interesting to me is that 9 out of the 10 largest churches have a multi-site format.  The only "church" (see yesterday’s post) that does not is Lakewood Church, home of Joel Osteen.  They seem to the the church right now with the largest television ministry so you could even argue that, in a way, they are multi-site.

http://theresurgence.com/md_blog_2006-09-07_multi-site_conference