Perhaps the last version of PicoContainer 2.x before focussing on 3.x, 2.10 was released earlier today. Changes:
1. String converters can now be overridden, and added to.
2. There's a new type of method injection that matches on method name.
3. The first piece of JSR 330 compatibility has been ushered it - the @Named annotation is recognized.
Aside from those feature changes, bugs have been fixed in FactoryInjectors and Provided lifecycles.