Henceforth I'm releasing all of my open source code under the terms of the GPLv3 (or later), or under the terms of the LGPL for library code where it makes more sense.
I don't plan on going back and changing the licenses of any of my existing projects. Nor do I have any popular GitHub projects, so I doubt this will change anything in real terms for anyone.
I'm not sure what will happen with my work projects. There are some things I'm working on right now (the Python memory profiler I've mentioned in previous posts) that I would like to open source at some point. The company I work for has a policy of only releasing software under the BSD/MIT license. At some level that's their decision---they have the copyright and therefore legal ownership of all of the code I've written for them. On the other hand, I plan to petition to change the licensing terms of such software if it comes to a point where we want to release it.
I've made this decision because recently I've come to the conclusion that software freedom is more important than corporate interests. I don't care about having popular open source software projects. I don't care about becoming a popular Hacker News blogger or becoming a tech celebrity. I don't care about enriching other companies. I don't care if using the GPL means that fewer people will want to use software I write.
However, I do care about software freedom; and I believe that releasing my own code under the GPL demonstrates that this is an important issue.