How to get a "modern" emacs that runs in a terminal on os x lion?
As far as I know, every emacs under the sun can run in a terminal:

/Applications/Emacs.app/Contents/MacOS/Emacs -nw


Change the path, of course, if your emacs resides elsewhere. If this is too long to type, even with tab completion, you can create a symlink to the Emacs executable, or make an alias for your shell.

Look to http://emacsformacosx.com/ for a precompiled modern Emacs for OS X.