Hey Andrei,
I have thought about investigating the possibility of making the admin a little more modular / flexible for plugins.
Here are my thoughts.
Add IAdminEntityPlugin<[EntityClass]> to the framework.
Extend the admin interfaces to detect plugins that use the interface for a specific area, for example:
A product plugin could be of IAdminEntityPlugin<Product> then the product editing screen could detect the plugin of that type adding it to the interface under a plugins tab for that edit screen.
The interface could have additional functionality to read and write data to the product using the new IGenericAttribute and GetAttribute features.
Let me know what you would think, if interested I could try to flesh something out in a fork.