There are some instances when it is justified for the government to keep secrets. Plans for future military operations that they want to keep out of the hands of potentially invading forces springs to mind. However, the government is theoretically supposed to be accountable to the people. When the government keeps things secret because they cast a negative light on its actions, it prevents any such accountability. The clamp-down on information surrounding the Bin Laden affair is just such a situation. This gives them time to concoct an "official story" that looks better than the reality. Hey, maybe they will say that he ordered attacks just minutes before his death. It already slipped that, had word not gotten out that Bin Laden was unarmed, the "official story" would have been that the mission was to capture him but that they had to kill him before he gunned them down. In other words, the government was going to lie to us.
On the other hand, there was an (unknown) real mastermind behind the attacks. It wouldn't take much for him to order attacks in the days following Bin Laden's death. After all, he is presumably alive and well. Over the coming years, there may be many attacks somehow "ordered just before Bin Laden died." And the public will eat it up. It doesn't make it true, though.
Another blogger actually wants more secrecy, rather than less. She thinks that at first no information should have been let out beyond "we got him!" Then, later, they could have presented the official lie that they were planning. Of course, she also asked what the big deal was that he was unarmed. Well the big deal is that, were they real soldiers, or Navy SEALS, they could have brought him back alive to stand trial. A police officer is not supposed to go around shooting unarmed suspects that he doesn't like. He is supposed to do everything in his power to bring suspects to trial. Now, a rogue officer will gun down innocent men and make excuses. And this is exactly what we see happening. Excuses are being made for why he could not be captured when clearly he could. And these excuses are being made after they make sure that no information can get out to contradict the "official story."