MySQL 5.1 in production already, then there is a use case competition that may interest you.The MySQL 5.1 series has a new release candidate:
You can check the changes we made in detail here:
Of course, our list of open bugs for the upcoming 5.1.29 release is online as well:
We welcome and appreciate your feedback, bug reports, bug fixes,
We also have an use case competition that may interest you, if you are using MySQL 5.1 in production already.