Copyright assignment is used by many projects, FSF included. Is there a comittment to the original authors to maintain an open source license in the MySQL case?
Not really. It was so, as mkurt explained, that MySQL AB could make money selling indulgences.
FSF is an exceptional case. In practice, however, dispersed copyrights are more effective for the user community because no one entity can wreak havoc through strategic neglect or minimal compliance.
There's a lot in a software system that is taken for granted that the GPL doesn't cover.
It's interesting. One possible interpretation is that dispersed copyrights may also create a situation where joint authors can violate the license with impunity. On the other hand, it avoids this: http://www.law.cornell.edu/uscode/text/17/203 (because getting a 50% quorum to revoke previously granted copyright license is going to be difficult indeed).
