As the Financial Accounting Standards Board's new version of lease accounting, which could add half a trillion dollars in liabilities to corporate balance sheets, moves closer to adoption, a study just released by Deloitte finds that only 7% of companies say they are "very prepared" for the changes. Final approval of the standard is expected later this year and implementation in 2014 or 2015.

That proportion may be "so low because many are waiting until the standard is finalized," says Josh Leonard, a partner in Deloitte's financial advisory services practice.

Waiting might not be such a good idea, Leonard warns, especially for companies that do substantial leasing of property or equipment. It would be smarter to begin preparing pro forma balance sheets, P&Ls and cash flow statements, he says. These companies should also start thinking about new or updated software for tracking and accounting for leases under the new standards, although that won't be available until the rules are finalized, he notes.