Currently, the entity reference module only displays the available options in the multivalue select widget in the order they were created. Once you start adding a lot of node options to the select field, this becomes unmanageable. Being able to sort by the node title would make life much easier. Even if it changed the only sort method from creation date to title, that would be a huge improvement
Module is still awesome without this sort. Just figured a quick line of code might make things easier for some.