I was attending a talk by Marty Thornley called “The Third WordPress”. Marty was talking about WordPress MU and the specific challenges presented when offering WP infrastructure for hundreds or thousands of sites. Offering themes, plugins, updates, etc.
Marty’s site is Photography Blogsites. This is a fascinating project. Photographers looking for a modern photography focused site service should consider this. Marty has built in many custom features just for photographers including branding, themes, and further customizations.