A few hours ago, Clang completed checkin 194194 to be feature-complete for draft C++14 including both language extensions and standard library features. (Note: The library conformance requires using libc++, instead of libstdc++ which is supported on more platforms but is not as conforming.) Congratulations to the Clang team for this achievement!
With this progress, it appears that the next release of Clang and LLVM, expected in December or January, will be draft C++14 feature-complete. C++14 itself may still undergo final changes at the February 2014 ISO C++ meeting, which is expected to be the final meeting for technical tweaks to the contents of C++14.