Hey,
we are working with THORMANG since the beginning. We’ve got already a lot of ROS-Software out which have been already used partly during the DARPA Robotics Challenge. Please check our organizations at Github: THOR-MANG · GitHub and DARPA Robotics Challenge Team ViGIR · GitHub.
For footstep planning, we’ve already fully open-sourced our 3D Planner: vigir_footstep_planning - ROS Wiki
In my opinion, a Humanoids SIG is a very nice idea, as still many software/approaches are not that easy to reuse for different humanoid robots as they probably could.
Best