• disable async support, and access to the underlying file descriptor under Windows. It's never worked reliably and ruby-core has a lot of work to do in order to make it possible.
• added support for turning eager-casting off. This is especially useful in ORMs that will lazily cast values upon access.
• added a warning if a 0.2.x release is being used with ActiveRecord 3.1 since both the 0.2.x releases and AR 3.1 have mysql2 adapters, we want you to use the one in AR 3.1
• added Mysql2::Client.escape (class-level method)
• disabled eager-casting in the bundled ActiveRecord adapter (for Rails 3.0 or less)