Bush rather casually decided that laws applied to him only as he saw fit. He was - with Cheney's seeming encouragement - an elected dictator. Rather than abide by laws, he apparently thought that as executive he could decide which of the laws applied. This was true even of bills that Congress sent him.
Obama might have just avoided falling into the same, "laws don't apply here" approach. Earlier, Obama said that he wasn't sure he wanted to open up investigations into the torture that was authorized by the Bush administration. Like Bush, he seemed to think that he had discretion about which laws to apply, which wrongs needed to be investigated.
The first step to returning the presidency to its rightful place as beholden to laws and the constitution is for Obama to set aside his squeamish feelings about possible prosecutions against Bush administration officials (including the panicked Dick Cheney). This is not his call and I'm glad to see that he's decided to turn this over to the Justice Department. Executives can't cherry pick which laws they apply.