Mapnik 2.0 has been released:

The Mapnik team is pleased to announce that Mapnik 2.0 is finally here! We’ve jumped from 0.7 to 2.0, not because we got confused with our numbers, but to reflect that this release represents a big step forward for the project. We believe Mapnik 2.0 will provide a much more flexible and expressive platform for creating beautiful maps.

For details you can read the milestone list or change logs. Unless you are under a rock, Mapnik is everywhere and used by everyone. FOSS4G 2011 was dominated by two projects, Mapnik and PostGIS. Good company if you ask me.