I attempted to install Emacs 24.4 through homebrew with the following command:
brew install emacs --HEAD --use-git-head --cocoa --with-gnutls
It ended up installing (a development build toward what might become) Emacs 25. I haven't been able to find any information about Emacs' roadmap, but since this version is in development I'd assume there is some sort of plan. What are the major features that are planned for Emacs 25?