According to Elevation DC, a mixed use project is set to break ground on the site of the old Greyhound terminal at 1005 1st St NE. This is on the block south of the "terminus"* of the Metropolitan Branch Trail at L Street.
The building will also have an elevated park open to the public, which a landscape architect is currently designing, Cohen says. "We're talking about a water feature and other features up there to activate it and make sure it's not just looking pretty."
What would be great is if this park could be accessed directly from the MBT with a bridge over L Street and then an at grade connection to K Street. I doubt that is in the cards, but one can dream.
*the trail actually continues to Union Station on both sides of the track, but it changes to an on-road and on-sidewalk trail at that point.