DC Streetcar article in the New York Times
"Washington Retail District's Future Rides on Streetcars," New York Times.
1. It will be the first modern streetcar on the East Coast, which is a big deal. Of course, who knew then it would take so long and it is neck and neck with Atlanta, although they won't be launching til the end of the year. See "Reed: Streetcar launch by December 31," from WXIA-TV and "Atlanta's streetcar launch, costs in flux," from the Atlanta Journal-Constitution.
2. It has the opportunity to reposition the H Street district towards retail once again--in the district's heyday it was the city's second biggest retail district and home to one of the first Sears Department Stores in the US and the biggest Chevrolet dealership in the country--because some retailers will see streetcar service as hip and something to be associated with.
For example, the Giant Supermarket at 3rd and H Streets NE "demanded" and paid for the addition of a streetcar stop to serve its location, and it's possible that some larger companies will see the advantage of locating there. Whole Foods Supermarket will be opening a store in 2016, and the current H Street Connection space is supposed to be remade into a mixed use project which provides the opportunity for a retailer upgrade.
More recently, H Street has been revived around nightlife and entertainment ("Plans to Set The Bar High On H Street NE," Washington Post) but it hasn't seen much improvement in retail, other than the opening of the Giant Supermarket and the Whole Foods announcement.
Although Downtown, especially with the gradual reopening of CityCenter, and the strengthening of retail elsewhere in the district ("Gap, Walgreens to open big stores downtown" and "Target considering a store near Metro Center in downtown DC," Washington Post) is a big competitor. The advantage that the nightlife element of the H Street district is that it brings many people to the area to sample it. The challenge will be to get them to come back at other times to buy goods rather than meals and drinks.
Many of the developers active on H Street now have strong retail portfolios and it is possible that they will bring that expertise to bear. For example, the project that Douglas Development is bringing to the 500 block includes retail ("Douglas Development plots H Street apartments, retail," Washington Business Journal).
... in the I told you so department, in 2003 back during the creation of the H Street Revival commercial district plan, they said that the 200 to 700 blocks would be residential. I argued that because there were relatively large lots capable of redevelopment and because of proximity to Union Station, that the area could accommodate high quality mixed use retail as well.
Looks like I was right.