I expect that at some point we'll see a conviction of someone from Enron. Probably on obstruction charges.
Remember, though...that while crooked as hell...what Enron was doing was perfectly acceptable under the law (for the most part). What you would have to prosecute on would be the "reasonable assumption of risk" language that surrounds the reporting of investment income.
With the right jury they might be able to get that to stick...maybe.
Same with Global Crossing. They were selling and repurchasing the same product in different periods to up their (false) revenue figures. Legal...but not at all ethical.
Those are the loopholes I mentioned that should be closed.