GNU and the General Public Employment Contract?

adubey asks: "We all know and love the GNU General Public Lisence. Some have argued that the availability of a standard lisence such as GPL along with hard lobbying work by Richard Stallman and others are both among the many forces that helped push free software forward. However, there is still a big laundry list of things holding free software back. Included on this list are restrictive employment contracts that forbid many developers from contributing to free software projects, even if some contributions could help them on the job. Rather than simply write off these people as being stupid for signing one-sided contracts, could we do something to pursuade managers to be more open to free software development? What if there was a standard contract available, between employers and employees, that spefically gave employees the right to contribute to free software projects so long as it benefits the company they work for?" An interesting idea and one that I hope will spark some interesting discussion. Would such a thing be the answer to this problem?

"Now, IANAL, but is it possible to have some type contract that says it would override any previous IP agreement? In other words, allow companies to keep current contracts in place, but overrides previous contracts in the one key detail that it will allow developers to release enhancements to free software packages, so long as the enhancements were developed for the benefit of the company (even if the enhancement - say a bug fix in gcc - is never released in itself)"