All that remains is for these vendors to put this mechanism to work directly on closed-source software, opening up the kimono first for close partners and trusted customers, and then for all interested parties.
This will be no small feat, mind you. Successful open-source projects like Mozilla worked because they fostered and then supported a fairly large community of contributors (developers, code testers, designers, etc.). The Mozilla project can count over 800 code contributors and thousands of testers. Contrast this with closed-source development efforts counting a handful of in-house developers and perhaps 10 or so key customers serving as beta testers.
The kind of transition necessary to add the scale and transparency enjoyed by the Mozilla project requires that vendors build software to support the creation of software. For Mozilla, it was the creation of Bugzilla, a bug tracking and reporting solution, that made the project go.
Some work akin to what went on within Netscape is happening now. IBM, for example, recently released Jazz, a two-year research project dedicated to building a scalable team collaboration platform for developers. Out of the gate, IBM intends to use this community and associated collaboration tools to foster innovation within its commercial Rational software product family through shared code, architecture, bug reporting, comments, ratings, and other collaborative tools.
Even if Jazz never turns the Rational product line into a commercial Mozilla (or more aptly, another Eclipse project), the prioritization of people in the development process and the transparency, accountability, and agility that emerges will go a long way toward delivering Rational and products like it from their supposed doom at the hands of the open-source movement.