All servers that are currently running MySQL 4.0 will be upgraded this month to 4.1 as a preliminary step towards support of PHP5+MySQL 5
cPanel and MySQL have had some compatibility issues lately, and as soon as these are resolved we plan to start the conversion to 4.1 for any remaining servers not currently on the mysql 4.1 tree.
This will bring us one step closer to PHP5 support that some of you have requested.