This is amazing news. I currently have to run 2 Jekyll installs to do what I want with custom post types (before this I had a fork to add a different type and that was getting hard to keep updated): I have one main Jekyll install for my blog, and inside of that inside /photos I have another Jekyll for my photo blog so I can do things like this:
Exactly the same message on DN: https://news.layervault.com/comments/62311