There are many more apartment buildings, for one thing.
Over at Washington City Paper's Housing Complex blog, reporter Lydia DePillis has pulled together some of the most interesting charts from the city's Office of Planning. It's worth reading through the whole thing, but this one chart illustrates just how many more apartments are being built. It's more than official, we're in a boom.
Kind of cool. Others show where the building is taking place and the city's changing racial landscape.