I\'m unable to highlight my assembly.
There is now a much better answer to this:
In Sublime Text, just go to Preferences > Package Control > install packages. Once there search for "mips-syntax" and hit enter on the result.
Once it installs you should be able to select MIPS as the syntax highlighting for whatever file you're editing.
Edit: Of course, this does assume that your Sublime has Package Control. You can get package control to do this and more at: http://wbond.net/sublime_packages/package_control