Looks like yet another new spot coming to the block of 14th Street NW between Spring and Quincy: Washington Heights Bar & Lounge. The city's DC Register included news that there's a liquor license application for the bar, which is coming to 3714 14th Street NW, two doors down from the Red Derby. That storefront used to be Quik Cash, a pawn shop of some kind, and before that was Salon de Belleza Union.
According to their application, they'll have American and French food and 42 seats. I don't have more information than that, but it seems like a step up from the pawn shop.
And oddly, the salon that was open before Quik Cash was one of those where Google Streetview went into the business with their cameras, so you can actually look around the space. It's long and narrow, much like the 'Derb. Here's the info from the DC Register, the city's official list of licenses, permits and so on.