Any bloggers with multiple WordPress blogs soon realizes the pain and time it costs to maintain the almost identical code base for each blogs when he has to take backups and upgrade his blogs. I was looking at various multi-blog WordPress solutions (not WordPress Mu)…

I couldn't find any solution which is simple to use and configure, allows me to maintain our existing blogs from a single code base and makes upgrade painless.

Do you know any such solution? Would you like to have one?

We need a solution to easily maintain our several (and growing list of) WordPress blogs which makes upgrade and backup (one code base to backup and upgrade is easier than multiple nearly identical code bases) painless. Also it should allow for existing blogs and wouldn't require anyone mucking into code. All plugins should work seamlessly out of the box and also all themes.