With news of the merge of the WordPress & WordPressMU codebase becoming more widespread, one of the questions I get asked with increasing frequency is should someone start a new site based on MU or should they wait for the merge.
My answer? It depends.
Is it time-critical? Do you need it up and running sooner rather than later? Is it income-generating? I spoke to someone earlier this week who is building out their MU-based site now because as they so succinctly put it, “I’m not leaving 3 months income on the table.”
And that’s how long it
will may take to be out in the wild. Can you afford to wait three months? Only you (or your client) can answer that.
Also, if you are planning a project based on Buddypress and were waiting for the merge so you could use it on single WordPress, I mentioned over a week ago that this improvement is already in the trunk of BP. It is tentatively slated for release at the end of January, so if that was what you were waiting for, I would start development on trunk now.
Other people I have spoken to expressed concern over being able to upgrade from WPMU to WP when 3.0 comes out. This is one of the major priorities for the devs, and I have found historically the devs were always quite good in making sure core code (and new changes) were upgradeable. They want your site to upgrade and succeed too.
EDIT: Although I said three months up above, the actual release date has yet to be determined. The length of time is an educated guesstimate, not a firm thing. It was stated for illustrative purposes for how long you may have to wait.