I've been using WPTwin to clone development sites to their live locations. In general, the site is developed on a subdomain (of my site or of the client's site). With WPMU I noticed the Cloner plugin, but it requires Multisite... which I've never used.
However, I have many new website designs coming up in the next 6 months, and if I can make the rollover of dev sites into their live locations easier with WPMU tools, that would be awesome.
I don't even know where to begin, though...
Ideas? Will this work? What would your recommended workflow be using WPMU tools?