On Tuesday, LLVM release manager Hans Wennborg announced the release of LLVM 3.8 Release Candidate 3. He mentioned, "If there are no regressions from previous release candidates, this will be the last release candidate before the final release."
So far things are looking good with LLVM 3.8 RC3 based upon the upstream developers/testers comments (new test failures reported appear to be not a new issue but tests that weren't running previously) and in my own tests the latest Git code appears to be playing quite well on Linux x86_64.
LLVM Clang 3.8 is home to some performance changes while more exciting than performance changes are the new features of LLVM 3.8. Expect LLVM 3.8.0 to be officially announced very soon, assuming nothing else comes up at the last minute.