Can Firebird gain against MySQL?

From Marco Cantu’s blog:

Now, this could be a very good opportunity for all of the other open source database servers (and also some of paid ones!), particularly the most popular ones like Firebird and PostgreSQL. I’m particularly fond of Firebird (the InterBase offspring) and use it in many projects and did a lot of consulting to Delphi developers using it. Can this be the rise of Firebird? MySQL with its huge popularity has certainly obscured it, so it could be a good time to act.