Only three release candidates were planned but a fourth RC was needed to address a Linux problem. The problem caused LLVM to break on all 32-bit Debian-based Linux distributions due to the Clang driver not finding a correct path. That's now been fixed along with other items so LLVM 3.5 RC4 was christened.
Due to this extra release candidate, LLVM 3.5 is past its due date but anticipate it will make it out in the next few days assuming no other blockers come about.
Those wanting to download LLVM 3.5 RC4 ahead of its official release in the days ahead can find the download links via the mailing list announcement.