C++11 may require some porting effort. I have seen code not compile under C++11, but mostly due to poor coding practices such as putting a "using namespace std;" at the top of a file (this caused an issue since C++11 includes a std::bind for binding functors but GCC 4.6 was unable to differentiate between std::bind and Berkley sockets bind due to the using namespace std). As far as I have heard, Visual C++ support for C++11 is also currently terrible, so we could be making it even more difficult to get ROS software up and running on Windows.

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.