MuleLover: aMule is an Open Source project with people working on this stuff in their free time, we are not Apple, who have many people working professionally on a project.
This means that we don't have a strict release plan, because we don't know when someone has the time to do something. But because all of us have a real life, work or university, friends, family and other hobbies or are moving/travelling, there's currently not much time to work on aMule.
We are struggling with some bugs which delay the release of aMule 2.2.0, which are not so easy to resolve, because we have insufficient debug capatilities for this bugs. Kry is working on broadening our development environments to get better debug capatibilities, but this might take a little longer.
aMule for Mac, Linux and *nix is on the other hand almost release-ready and you can safely use current developmental versions.
Conclusion: It is done, when it's done, please use a developmental version in the meantime.