As was posted above, they have a store front, but when I was there about a year and a half ago they didn't have a huge selection. They had all of the Don Pepin black/blue/white labels and vegas cubanas, but they only had Tatuaje brown Noellas and Tainos. Although, I agree that it is a must visit.
Also, you should stop in El Credito right down the street, which is the La Gloria Cubana Factory, that place is beautiful. I also recommend stopping in La Luna cigars, Gael, the owner, will probably be around and be in for some interesting conversation. He also blends some top notch smokes.
Have a great time.