I'd love to be able to build distributable packages (with dependencies) with homebrew as I can with MacPorts. It would allow me to finally ditch MacPorts all together as I often need to send end users a package.
You can build individual binaries using bottles. We're not going to implement this but would accept a pull request.
It's a shame there's no easy way to do this. This is essentially the only reason I include MacPorts' installation of Samba instead of Homebrew's: I can't create an MPKG out of Homebrew's to distribute instead.
I have just discovered brew-pkg. I haven't tried it yet but if it works, it may be useful for those checking out this thread in the future: