I have three separate blogs with one database. each SUBblog has its unique identifier in the database( although I am not entirely sure this accomplishes what I want). The concept is simple...
The most important thing here would be to be able to cross post from just one "writing pad". A "place" where I could collect all my drafts, links that I will blog about as soon as I get a chance. I'm even fine with setting up different blogs with their own adminpage, template handling and more, if I could just write from just one spot. I usually don't tweak the blog's appearance that often.
And would it be possible to easily file permalinks to comments I write across other people's blogs, and maybe even "suck them back home". Not that my comments are so great all the time, but it's annoying to loose track of all the conversations. I know there's cocomment and probably others out there, but it seems to me that WordPress could become a "control room" for my writing. Everything appearing as a separate domain, but controlled from one MAIN place.
I hear MU is NOT the way to go, especially for 5 or 6 blogs.