DC has a new, young whippersnapper of a mayor--Adam Fenty. In his quest for excellence he went off to NYC and listened to Mr. Bloomberg, saw his "bullpen" office, and is reproducing it in DC. See this Post article by David Nakamura, who does a good job in considering the pros and cons.
The intangibles of space and schedule impact the work. I remember working in an office where we all arrived at the same time (before Flexitour, etc.) and all were coffee drinkers. So we (5 of us) had a natural staff meeting around the coffee pot to exchange information and get on a common footing. It made the office work.
Bloomberg seems to have done well in NYC. But he's older and has much more administrative experience than Fenty, who's only run his council member office. My guess is that the bullpen won't work as well for Fenty, who's going to have to learn on the job. It is, however, a valuable symbol for him. He wants a rep as the shaker and mover and this will help.