Although I realize it is likely too late, an alternative to forgoing the incentive clause under your employment agreement would be to instead accept the $60 million, and set up a lottery for Enron employees in which 30 winners would each win $2 million (or some variant, i.e. 10 winner for $6m, 120 for $500k etc.).
This could be done for employees of record at the time of the merger.
The idea clearly has pros and cons, but on the whole I feel would create some positive news for people to focus on in this difficult time. It would certainly be a non-traditional and positive way to close the Enron era.