I'd suggest looking at the papers that were submitted for discussion at the upcoming Lenexa Standardization meeting for references. They're located here: https://isocpp.org/blog/category/standardization

Here's numbers for the ones you listed:

Concepts: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n436...

Modules: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n446...

Coroutines: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n439... & http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n439.... Also http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n413...

operator dot: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n447...

Uniform call syntax: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n447...

Here are some others that Stroustrup listed. I think they're probably important proposals. I imagine Stroustrup has at least some priority order in his list.

Ranges: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n438...

Comparisons: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n447... & http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n447...

array_view: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/n434...