Easily edit the "Enter Title Here" message when editing a post based on post type slug. This example uses "szbl-location" as seen in my WordCamp San Diego 2013 presentation.

enter-title-here.php

<?php
add_filter( 'enter_title_here', 'szbl_enter_title_here' );
function szbl_enter_title_here( $title )
{
    switch ( get_post_type() )
    {
        case 'szbl-location':
            $title = 'Enter Location Name';
            break;
    }
    return $title;
}