Webpronews.com: This appears to be a strategic move by Oracle to put MySQL between a rock and hard place.
Innobase is the company that provides the underlying code for the InnoDB storage engine in MySQL. It's the de-facto choice for developers who need high concurrency, row-level locking, and transactions in MySQL. For many years now, MySQL AB and Innobase Oy (founded by Heikki Tuuri) have worked closely together to make that technology a seamless part of MySQL.
Like all of the MySQL code, InnoDB is dual licensed. That means you can freely use it under the GPL or buy a license for it if your usage would violate the GPL.
MySQL's public reaction right now isn't the "holy f$@%ing shit!" that likely occurred internally. Kaj Arno, MySQL's VP of Community Relations, sent out a message to many MySQL users today titled " MySQL AB Welcomes Oracle to the FOSS Database Market".