Wendy Thomas has been the perennially childlike face of Wendy's for ages, but until now, she's never been in an ad for the fast-food chain founded by her father, Dave Thomas. That changes next week, though, because Wendy is set to appear in three Las Vegas-exclusive commercials (created by The Kaplan Thaler Group) for the Dave's Hot 'N Juicy Cheeseburger, which the rest of us provincials won't get to try until next summer. Vegas is often a test site for new menu items, which Wendy's svp of communications Denny Lynch says is because of its "broad spectrum of people." Wendy herself thinks Vegas has "a great demographic. You're young, you're old. You have everything here." And since the city indulges so many other unhealthy appetites, what's a new cheeseburger here and there?