Just received an email newsletter from Sun titled "MySQL 5.4 Preview Release" which states:

Sun Microsystems recently released MySQL 5.4, delivering performance and scalability improvements enabling the InnoDB storage engine to scale up to 16-way x86 servers and 64-way CMT servers.

MySQL 5.4 also includes new subquery optimizations and JOIN improvements, resulting in 90% better response times for certain queries.

Apparently, the confusion about the contents of the release I wrote about earlier continue to reign inside Sun as well. MySQL 5.4 has not been released by any reasonable meaning of the word, since there's "only" a preview available at this time. Compare this to Windows 7: that's already a Release Candidate, but it has not been released. Also, the preview release available does not include new subquery optimizations nor JOIN improvements. Having planned such improvements doesn't count.

As I wrote earlier, the best of the rather bad excuses for the release labeling offered to me was that Sun wanted to avoid confusion by not releasing many versions at once. I think that got replaced (and then some) by plenty of extra confusion about when and what was released, instead. Sorry, no good. Try again, 'kthxbye.