Chris Lattner's first paragraph here talks about that a bit, although it doesn't give a timeframe for when the gcc implementation will make its way back to the main distribution:
Although, there's a comment by Johannes Fortmann here that says that the code has been available in an svn repository since at least September 5, 2008:
http://lists.cs.uiuc.edu/pipermail/cfe-dev/2008-August/00267...
Although, there's a comment by Johannes Fortmann here that says that the code has been available in an svn repository since at least September 5, 2008:
http://mooseyard.com/Jens/2008/08/blocksclosures-for-c/
"If you check out the llvm-gcc svn trunk, you’ll find all the code there (you can even build your own llvm-gcc with working blocks)."