>>The question isn't whether or not regulation is lax and whether or not this happened, it's how to fix it.
In my opinion the only way to reliably fix this is to create a group similar to the one that the federal government created to end Al Capone's illegal activities during the Prohibition.
That group was nicknamed "The Untouchables" because they were fearless and incorruptible (by reputation, which is what's important). They were hand-picked by Eliot Ness, who reportedly went through the records of hundreds of Prohibition agents and personally identified a small group of them who were known for their honesty and integrity (as well as special skills, such as car tailing). What's remarkable about this group is that they were not only stubborn as hell but also extremely resilient to Capone's attempts at bribery and intimidation. Ness himself declined a bribe that was equal to his salary but would be paid to him monthly. They had a huge impact on bringing down the kingpin.
It's pretty clear that the regulators in charge of overseeing the financial industry today don't have this type of drive. To them, it's just a job. They are normal men and women who are up against groups of massive political power. As such, they are not in a position to do their jobs effectively. That's why the system is rife with rampant corruption.
Before you say I'm dramatizing, consider the possibility that Enron was just the tip of the iceberg, and under the surface there is ten Enrons that are propping up huge sectors of the economy with lies and deceit. Maybe ignorance is bliss and we should just let it operate like that. But truth has a habit of coming out sooner or later - and the sooner it comes out and everything comes crashing down, the sooner we can rebuild the system.