For the time being, version 5.0 is only available in source code. See 項2.3.4. 「開発ソースツリーからのインストール」.
The following changelog shows what has already been done in the 5.0 tree:
Basic support for stored procedures (SQL-99 style).
SELECT INTO list_of_vars, which can
be of mixed, that is, global and local type.
Deprecated the update log (no longer supported). It is fully replaced by the binary log.
User variable names are now case insensitive: if you do
SET @a=10; then
@A; will now return
course, the content of the variable is still case sensitive;
only the name of this variable is case insensitive.
This is a translation of the MySQL Reference Manual that can be found at dev.mysql.com. The original Reference Manual is in English, and this translation is not necessarily as up to date as the English version.