Some interesting views from Paul Vallee, chairman of database support services provider The Pythian Group, about the currently stopped takeover of SUN by IBM:

Excerpt:

A stronger MySQL wouldn't hurt DB2's new customers, since there aren't many, 
Vallee said, nor would it cause many existing customers to consider a lengthy, 
tricky migration.

MySQL could hurt Informix, which IBM acquired in 2001 to help it regain the database 

Just saw this:

IBM 'in talks' to buy Sun Microsystems

Different editions of MySQL serve different purposes. MySQL is currently offered in two editions:

• MySQL Community Edition

This edition is distributed under the GPL. It could be downloaded and used without charge for test, development and production environments. However support is only available thru the MySQL community.

• MySQL Enterprise Edition

This is a new series published on The Informix Zone. The purpose of this series is to take a deeper look at the popular open source DBMS MySQL that is now owned by SUN Microsystems.

MySQL's Popularity and Weakness