Mary Jo White, former United States Attorney for the Southern District of New York, has been tapped to serve as the new head of the Securities and Exchange Commission. It's difficult to be certain, but it seems like a move in the direction of tougher enforcement. White's been in the private sector for ten years and thus no doubt has her share of industry ties, but her main professional background has been in government.
What's more, it's symbolically significant to choose a prosecutor for the post. As a federal prosecutor in both Brooklyn and Manhattan she oversaw cases against everyone from John Gotti to Ramzi Yousef. She doesn't lack experience with Wall Street—in fact, she prosecuted some high-profile securities fraud cases—but her interactions with it were a subset of her overall prosecutorial brief. Finance doesn't come to the attention of the US Attorney's office unless the point is to crack down hard—you don't go there for a rubber stamp, and banks aren't lobbying the US Attorney on a day-to-day basis.
The Obama administration isn't going to engage in a radical ideological reinvention, but as we get farther from acute financial crisis I think you'll see less worry about propping the financial system up and more concern about avoiding the next crisis. White's appointment should be seen as part of that trend.