A wizard to help set up the JOSM environment for mapping public transport and other route relations

The double split map mode

Various bug fixes and improvements

Routing Helper , which can be invoked from within the Relation Editor.

This last addition may have a big impact on how bus itineraries are mapped from now on.

User Polyglot is creating screencast videos to show how it works and with various tips and tricks, both for working with JOSM and for mapping route relations in particular. They will be linked from the wiki documentation page.