MultiSite CMS?

I have wordpress installed in the root directory of my server. The main blog is going to be used to “feature” articles posted in the daughter blogs. What I don’t understand is, once the blogs are created with Super Admin, is there an easy way to repost them on the main blog? I want comments and discussions to be shared between the two blogs, but only on posts that I deem “featured”. Anyone know how to do this? Does it even make sense? 🙂