Just a quick prompt to hear what other folks think of the Network option that replaced WPMU.
I've set it up and have been working my way through a few issues with DNS for independent domains (rather than as sub-domains or sub-dirs of the primary) but I can see that once I figure out the process, this will be quite handy. Especially when applied to a network of sites that have a similar theme/topic and could benefit from drawing on the same database for ad delivery.
While I haven't tested this yet it seems that copy could be posted on more one site if users have permissions on the other sites.
I'm having a bit of fun with this because it opens up some doors that I hadn't considered before.
Hmmmm . . . I may/must have picked up a bit of misinformation that indicated the new release only works "as MU" with subdomains, not independent domains. That was a bit of a disappointment to me, so I'm happy to read your comment suggesting otherwise.
Down at the bottom of that page you'll see a few extra resources to follow up on. One of them is [wordpress.org...] Follow the instructions - might take a bit of fussing the first time to get it working.