This plug-in looks really cool. Something I'm having a bit of trouble understanding is how page-level caching works with memcached. It looks like the enhanced disk-level caching works like wp-super-cache, in that it generates a hierarchy of cached files and uses Apache rewrite rules to serve content directly from there. I'm not aware of Apache being able to serve content directly out of memcached though. So how does that work exactly?
I haven't managed to find any documentation that explains how this works, but if there's something out there I missed, a link would be greatly appreciated.