One of the really cool things that you will be able to do with version 4.0 of the Repository module is add entire new functionality without ever laying eyes on the code. The 4.0 template engine supports the dynamic loading of custom controls which enables you to extend the module to your heart's content :)
Currently, if there is some missing functionality from the module, you would have to edit the module's source code itself, adding support for a brand new token, then rebuild the module and upgrade your DotNetNuke site to use the new token. Then if a new verison of the module came out, you'd be in trouble. Now, with the ability to load controls from within a template, you can extend the module to add new tokens by writing your new code and compiling it to a .dll, dropping your new control .dll into the bin folder and now you have a new token to use in your templates. There is no limitation to the functionality you can add using custom controls.
I put together a brief ( 11 minute ) video demonstrating a couple of very simple examples, but hopefully by seeing how easy it is to develop external custom controls and then use them within your Repository templates, you will see the unlimited potential of this new version.