I’ve been running a few instances of WordPress MU for a while now, so I was more than a little anxious about the merge of the MU functionality into the core of WordPress. It’s a good thing, but sometimes such dramatic changes pose rocky challenges.
Not so in this case.
Pete Mall blogged about it in May, and I’m happy to say that I followed those instructions (summary: upgrade, it will work) to upgrade both this site and Scriblio.net recently. The biggest challenge I faced was in migrating my SVN checkout (not discussed in Pete’s post, but people who install via FTP or use the auto upgrader don’t need to worry about this), and Pete noted the only gotcha that I might have encountered: changing the .htaccess to use a different file that had been used in WPMU.
I tested the migration on this site, and it rocked so much that I decided to go forward with upgrading the other site, even though WP3.0 hasn’t been formally released yet. Rock n roll.