Shake Shack will open their first MoCo location at Cabin John Mall in Potomac in mid to late 2018 (http://storereporter.com/shake-shack-heading-cabin-john-plus-sushi-burritos-last-call-smoothie-king-sears-update/).
Founded just 13 years ago, the New York City based fast casual restaurant chain now has almost 150 locations across the world. They've finally made it MoCo. If this goes well I wouldn't be surprised to see 1 or 2 more locations within the county (maybe Downtown Silver Spring and Crown in Gaithersburg?).