I was told that Ubuntu 11.10 comes with MySQL 5.5 but it doesn't show up in the cache search. Did it not make it in to the latest release?
root@ubuntu:/etc# cat lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=11.10
DISTRIB_CODENAME=oneiric
DISTRIB_DESCRIPTION="Ubuntu 11.10"
root@ubuntu:/etc# apt-cache search mysql-server
mysql-server - MySQL database server (metapackage depending on the latest version)
mysql-server-5.1 - MySQL database server binaries and system database setup
mysql-server-core-5.1 - MySQL database server binaries
auth2db - Powerful and eye-candy IDS logger, log viewer and alert generator
cacti - Frontend to rrdtool for monitoring systems and services
mysql-cluster-server - MySQL database server (metapackage depending on the latest version)
mysql-cluster-server-5.1 - MySQL database server binaries
torrentflux - web based, feature-rich BitTorrent download manager
You are right, 5.5 is not officially in 11.10. See http://packages.ubuntu.com/search?keywords=mysql-server&searchon=names&suite=oneiric§ion=all and https://bugs.launchpad.net/ubuntu/+source/mysql-5.1/+bug/690925 for instance. The latter URL suggests it'll be in 12.04 hopefully (which would be nice, since that's an LTS if I am not mistaken).