Enron is dead and buried, right? We’ve been dancing on that grave since the energy giant went belly-up in late 2001. Sarbanes-Oxley took hold, corporate America was put on notice, and the story of Enron became a cautionary tale for financial ne’re-do-wells.

So what’s that smell?

According to Bethany McLean, it’s awfully familiar … and more than a little frightening.

McLean, Fortune magazine’s editor-at-large and co-author of the riveting book The Smartest Guys in the Room: The Amazing Rise and Scandalous Fall of Enron, has written a commentary titled “Uh-oh. It’s Enron all over again,” in which she compares the current credit crunch with Enron’s smoke-and-mirror finances. She fears there are far too many similarities for comfort.

The problem, says McLean, lies in structured investment vehicles, or SIVs. These are off-balance-sheet entities that, some say, helped lead to the recent credit and housing boom … and may be to blame for the credit crisis that has followed. Enron’s value was buoyed by similar off-balance sheet vehicles called “special purpose entities,” which helped hide the true nature of the company’s finances.

“In both cases,” writes McLean, “part of the problem was that the rating agencies, which are supposed to serve as watchdogs, were blindly optimistic. Just as Enron’s investment-grade rating — which it kept until four days before its bankruptcy — turned out to be an illusion, so did the investment-grade ratings on many mortgage-backed securities. … (N)o one wants to remember two simple rules — some things are too good to be true, and be wary of Wall Streeters bearing gifts — when everyone seems to be making so much money.”

Read McLean’s article, then tell us: Do you agree? Have investors and financial executives forgotten the lessons of Enron, or is this something different?