This is actually a question each and every maintainer of a ROS packages has to answer.
We (at OSRF) are currently working on a lot of “foundational” stuff: basically what is enumerated on the roadmap. While we try to demonstrate the usability and improvements using demos we don’t maintain many of the higher level packages in ROS.
E.g. for rviz we are trying to rewrite the existing code base to support both ROS versions (see https://github.com/ros2/rviz). But each component (navigation, moveit, etc.) will have to come up with their own plan. For other packages like rqt we haven’t even started to plan how to support ROS 2 with it.