The financial-reporting community has good news to celebrate this spring, with restatements falling 27 percent in 2009 to numbers not seen since before passage of the Sarbanes-Oxley Act in 2002.

The question now is whether those numbers are only an inflection point, destined to rise again in coming years as the full force of the financial crisis and recession settles in—or whether all those investments in internal control really have led to lasting improvement in financial reporting.

2009 saw only 674 restatements, down 27 percent from 2008 and down 62 percent from the peak of 1,795 restatements in 2006, according to ...