I've been tossing around in my head an idea for a Jewish blogger site that gathered multiple blogs together in a better community format.
My first attempt at studying the structures and software out there was to install XAMPP from Apache Friends on my machine and try WordPress MU on it. The bugs and problems were many but thanks to relatively good Google-Fu, I managed to fight my way to what I found to be a common problem of such things: blind spot in smtp linkage.
No plugin I could find would allow external SMTP server usage for it, all were apparently written for regular WP.
Also, it creates subdomain blogs as in user.domain.topdomain and has no system to properly tie them together that doesn't involve immense geekery and I spend enough time entering things of the sort, ip route 192.168.10.0 255.255.255.0 10.10.2.1, all day long. I don't want to have to master PHP programming on top of everything else I do to make something as simple as WP on Apache work.
So, fail. Big time fail, WP. On to phpBB version whatever.