Usually when I add a template, I want to add more than one of it. Instead of manually filling it out each time, it would be nice if some of that white space was dedicated to listing a few of the templates I might want to use again.
They're similar ideas in that they fill the white space with suggested templates (so perhaps worth lumping together), but while community-defined defaults might be fine for new users, the list should be able to change by looking at the previous templates you've invoked. (I.e., if you only add specific templates to articles.) One of the benefits I see VE (eventually?) having for most users is the predictive ability to know the template you want even when you don't remember its name.