All Aboard: RTD’s N Line Starts Rolling From Denver To Thornton – CBS Denver with a bit of video of the ribbon-cutting and the trains and action.
RTD N Line Phase 1 Bridges Denver With Thornton - Railway Age - shows the 2-mile Skyway Bridge in the line - single track.
The N line is done out to Eastlake, about 13 mi from Union Station, and a second phase will extend it 5.5 miles further with 2 more stations.
The remaining Fastracks extensions are the light-rail L Line from its current end to the A line, the light-rail Southwest Line into Highlands Ranch, and the commuter-rail B Line from Westminster to Boulder and Longmont. The latter line will likely be done by DMU instead of by EMU.