If I recall correctly the lead programmer on the visual studio team stated that some C++11 features were too difficult to implement (I believe it was variadic templates). I don't except them to have C++11 support for a long time, even though it seems they are already adding C++14 features.
I don't think it's that it was too difficult, but rather too difficult to accomplish within the release timeline.
When he gave that statement GCC and Clang already had that feature for 3-4 years. Time can't really be said to be a factor when two other compilers both became feature complete around the same time, except for visual studio.