The Abdera Apache Incubator project is now up and running. The project is to provide tools for The Atom Syndication Format and The Atom Publishing Protocol. Right now I'm mostly contributing by maintaining the Maven build configuration for the Java implementation. I hope to be able to do a little more later (especially once the World Cup is over...)
I'm convinced that there's a lot of potential for uses of these two standards (well, soon-to-be-standard in the case of the publishing protocol), beyond blogs & aggregators. Having a good Java library for working with this stuff is going to enable a lot of applications, and save a lot of time and money for tools and products built on Atom. Open source projects succeed based on participation, so if you might need to use Atom, then please, come join in. It's just getting started, so it's a good time to get yourself familiar with the code and get your ideas into the mix.