It's also possible (although I considered less likely until around now) Oracle will simply cut off support, new versions, and patches in the future unless you pay, and recent work on it has only been to reassure the existing customer base into not switching to MariaDB/Percona/Postgres.
Given how simple it is to drop in MariaDB/Percona Server without changes, this wouldn't be a terribly sound strategy.
A better strategy is the one they currently use - selling support tools (like Enterprise Support, Enterprise Monitor, and Enterprise Backup) to support the development. It never ceases to amaze me how much people will pay for these tools and services to support a OSS product.
