I'm aware of a plea bargain a couple of weeks ago. But Worldcon was a much more recent scandal and the results have been much more swift.
Enron didn't have obvious misstatements like WorldCom and Tyco, but rather hundreds of sub-partnerships. It takes longer to go through those and find the illegalities. Also, some of what Enron did was unfortunately legal, although unethical.
I imagine the plea bargain is to get more information on others. Otherwise, what is there to bargain with?
Could just mean the Enron crooks were smarter than the World Com Crooks. There will be arrest of Enron officials. Let them do the job right so it sticks.