What I find fascinating in this debate is the concept, or fear, that GPL software will somehow disappear.
Let me take an example from history, the MySQL vs Progress case where Moglen wrote the MySQL affidavit. Here is a link to the affidavit reference that Moglen supplied to the court.
A synopsis of this is that, Progress had released at the time a version of the MySQL Database which included their Gemini Storage Engine. They had not though provided the source code to the Gemini engine. This was a violation of the GPL. Progress lost their case and later made their engine available under the GPL. The engine is still available under the GPL. I made a point of putting a copy up on the Internet years ago (and I know that there is a Russian company the uses the code). It is a fairly old version of Progress's current product, though from talking to one of their architects a couple of years ago, the code has not changed considerably.
So here we have a company's database product still being made available under an open source license years later. This is the Lazarus Phenomenon, whereby open source when published, has the potential to exist forever. The open source license allows for anyone to continue to make the Gemini code freely available under the constraints of its open source license.
Having more insight then most into the history of MySQL, I find that there are a number of twist and turns that can be found in all of this.
When MySQL was concerned about the Oracle acquisition of Innodb, it looked into alternative engines. One of the engines we looked at was the Gemini Engine. Why did we look at it? Since Progress had open sourced their engine we had the option to use it. An option that history has shown was never needed, since Oracle has continued to develop Innodb. It was an option though, and we looked at it. We had that right.
As another example, when Galbraith left MySQL, development of the Federated engine collapsed. When it became impossible for him to provide back contributions to the engine because of his lack of employment to MySQL, what happened? He forked Federated to create FederatedX, which is still developed and distributed today. Even though the version of Federated has remained nearly static in the main tree for years, his version continues to be enhanced.
When Monty and David changed the license on the MySQL network drivers from public domain to GPL, the PHP project and Redhat continued to distribute the public domain version for years (I believe Redhat still does).
The entire concept of taking what has been made publicly available, and somehow removing it from the commons is inane. It makes me think about how American Society of Composers, Authors & Publishers tried to sue the Girl Scouts for singing songs around the campfire. Once the tune is in your head, it stays in your head.
Once software has been published under an open source license, it continues to be available, whether its current owners wish it to be or not.