This is actually not news, MySQL was already headed down the closed source path with the introudction of Enterprise MySQL, and started releasing some closed source code on that basis in August of 2007.
The article is infamitory, and looks to be intended to generate flames more than anything.
I'm actually more concerned about what Oracle has planned for InnoDb. I see that as a MUCH larger risk to my use of MySQL than anything that Sun has announced so far.
Oracle tends to be a lot more creative in extracting money from clients than Sun does, and InnoDb is critical to what I need now while Sun's new features are not even available yet, much less critical to me.
Sun and Oracle have different but quite interesting positions on Open Source. I don't see either of them as being really good for the community, but that is only fitting because they need to be good for their shareholders. Like many things in the database world, it will be interesting to see this one play out!