His work is already in an advanced stage, time to take a look and show you, what's possible.
Note that the scope of the project is to provide a plugin infrastructure. Part of this is a very basic example plugin, but not with any advanced functionality.
The installation is easy, if you want to test it, you can checkout Leonardo's code from his git repository.
If you want to see the example plugin, you have to activate it in config.inc.php:
The config option is the plugins variable, new at the end of the file: $conf['plugins'] = array('Example');
After enabling this option, you will see a new link "Example Plugin" appearing at several places:
This links show basic functionality, like some links to itself (showing how to build links using the new link infrastructure). This should give other module developers an idea, how to develop modules. The example plugin always adds the new tab on the most right position.
Conclusion: the infrastructure is available. Now it's time for you module developers to actually write some useful modules ;-)