While no official announcements have been made yet about the state of C++17, previous communications have signaled that C++17 should be considered technically complete by the time of the ACCU conference happening at the end of April.
For those curious about C++17 changes, a nice at-a-glance look at the changes can be found via this GitHub repository.
C++17 is bringing parallel versions of STL algorithms, new special math functions, initializers in switch and if statements, and more. GCC 7.0 and Clang 4.0 are already in quite good shape for C++17 additions thus far. More details when any official C++17 status update announcement is made.