Because the 2012 Citi Open is taking place at the same time as the 2012 Olympics, there aren't a lot of big name players at the tournament, but there are some quality players in Washington, D.C. for various reasons. In the case of Mardy Fish, it's because he wants to focus on his hard court game in the run-up to the US Open, and the Olympics are being played on grass. In the case of a few others, like Alexandr Dolgopolov, their country didn't select them to play.
The men's draw is quite a bit deeper than the women's draw, which has been almost entirely depleted by the London games. The highest ranked player is Anastasia Pavlyuchenkova, the 28th ranked player in the world, and there's only one other woman in the top 50 in the field. In the men's field, seven of the players are ranked in the top 50.
Television coverage starts with the men's round of 16 on Thursday on the Tennis Channel. The final will be broadcast live on ESPN2 on Sunday. The women's tournament is not televised, likely because of the low quality of the tournament.