The MySQL marketplace today is far more complex then simply choosing between a particular version of MySQL that Sun/MySQL (http://mysql.com) produces.
The MySQL server product in general is released under the GNU General Public License (GPL) v2, however you should carefully review the MySQL Legal Policies (http://www.mysql.com/about/legal/) as a number of exceptions and different license agreements operate for companion tools such as MySQL Cluster, MySQL client libraries and documentation for example.

Looking into the MySQL ecosystem for products, I’ve produced the following categories:

• Sun/MySQL Official Products
  • MySQL Versions
• MySQL Variants
  • Community
  • Enterprise
• MySQL Plugins

I’ll be following closely the progression of Storage Engines available in the MySQL Database server, well soon to be available when 5.1 gets to GA (hopefully by end of Q2 which is what we have been told). Tick, Tick, time is running out.

PrimeBase XT (PBXT) and Blob Streaming is obviously my clear focus, actually now working for PrimeBase Technologies, the company which I want to note for people is an Open Source company, committed at providing an open source alternative to the other commercial players. You also have at the MySQL Conference talks on the the existing InnoDB from Innobase (a subsidiary of market RDBMS leader Oracle). There is a