1. Install MacTeX from http://www.tug.org/mactex/
2. Add the MacTeX directory to your path. For me it is /usr/local/texlive/2010/bin/x86_64-darwin/ for 64-bit Intel or /usr/local/texlive/2010/bin/universal-darwin/ for everyone else
3. To make MacTeX play nice with Homebrew, change the owner of all files in /usr/local "sudo chown -R $USER:staff /usr/local"
4. Install HeVeA "brew install hevea"
5. Symlink HeVeA so that MacTeX can find it "ln -s /usr/local/lib/hevea /usr/local/texlive/texmf-local/tex/latex/hevea"
6. Run "mktexlsr" so that MacTeX finds HeVeA

You can follow our progress at: https://www.pivotaltracker.com/projects/224875/