I've been thinking about making a map, but I'm wondering how long it would take before I start on it. If I made a map from an .svg file, for example this one: http://upload.wikimedia.org/wikipedia/commons/0/0d/Iran.svg

About how many hours do you think it would take to turn it into a Warlight map?

A few hours, maybe a day, depending on your learning curve :-)
That map already looks clean enough, so wouldn't have to make too many adjustments.
Assigning the names, grouping territories to bonuses, finding missing connections and balancing the bonus values might take the most of your time.