Brooks Davis mentioned on the FreeBSD src-head mailinglist a few days ago that November 5th was going to be Clang-day and that he was going to make Clang the default compiler for FreeBSD 10. He has now committed the patch as promised.
This change follows a few years of preparation, feeding back improvements to the Clang and LLVM source code bases, and nightly builds of FreeBSD using LLVM over two years. Future snapshots and all major FreeBSD releases will ship compiled with LLVM by default.
After years of hard work by many FreeBSD and LLVM developers, make clang the default compiler on i386 and amd64 systems.