None of the Humble Bundles actually include the source code with the purchase. Sometimes the publisher has released the code of the games included in the bundle on their own outside of the actions of the Humble Bundle.

The reason that Jack Claw in this bundle was open sourced is because it is a prototype.

You can find sourcecode for games included in other versions linked from Wolfire's blog:

http://blog.wolfire.com/2010/06/Aquaria-goes-open-source http://crypticsea.blogspot.com/2010/05/gish-open-source.html http://blog.wolfire.com/2010/05/Lugaru-goes-open-source http://frictionalgames.blogspot.com/2010/05/penumbra-overtur...

As far as I know, the second Humble Bundle did not include any games of which was later open sourced.