>  One question would be whether a move to C++11 would entail the default catkin flags adding "--std=c++11" (and thereby compiling the entire ROS ecosystem under the new standard) or it would simply be a "you may use it if you wish" and let people manually flip it on.

I'd like to be as permissive as possible for user code, so forcing C++11 seems counter-productive.

However, testing with C++11 turned on seems quite worthwhile, so that should be settable at some high level.