$ brew install tbb
==> Downloading http://threadingbuildingblocks.org/sites/default/files/software_
curl: (22) The requested URL returned error: 404
Error: Download failed: http://threadingbuildingblocks.org/sites/default/files/software_releases/source/tbb41_20130613oss_src.tgz
Looks like an upstream problem, because when I go to the homepage and click on download and select the source version, I am brought back to the homepage.
Can you report that upstream?
tbb: Adding macports mirror