The DC region failed to win a TIGER II grant that would have been used to expand the system from 1000+ bikes to 3600 bikes (bicycle and pedestrian projects only got 4% of the money). That's the bad news.
The good news is that the region's leaders considered this important enough to propose for the grant. They did a study showing that it would be incredibly cost-effective, something that advocates can point out when they ask for local governments to fund an expansion. Other good news is that DDOT is committed to finding a way to expand the system in DC. And that could be TIGER III. [Update: WAMU has a story on how the process was valuable]
What people should do if they want to see the expansion - or something similar to it - happen is write a letter to their local decision-makers (such as DOT's, the TPB or elected officials) and:
1. Thank them for supporting the TIGER II application and bike sharing
2. Tell them how important bike sharing would be in your area
3. Ask them to find another way to fund an expansion - even a more modest one.