Just before the holiday's MySQL refined its licensing scheme from “GPLv2 or later” to “GPLv2 only“, in order to make it an option, not an obligation for the company to move to GPLv3.
Specifically, this means that copyright notice in the MySQL source code files will change from referring to “either version 2 of the License, or (at your option) any later version” to “version 2” only, in the MySQL 5.0 and MySQL 5.1 code bases.