It took really a breeze to implement a custom resource provider to replace default RESX-based one. Really, I didn't think it could be so easy! Kudos must go to .NET framework engineers because you can literally customize basically any aspect of the framework, down to every basic detail. Microsoft can be great when they really want...
So Diavolo localization system basically integrates with standard system one and that means developers can use everything they are used to : implicit localization, explicit one, programmatic access. Everything is supported while developers can access and modify data at runtime without any need to restart application or influence performance.
As a reference, I used Michèle Bustamente's article about custom resource providers: you can read that article here. It's a very nice article and tells basically everything you need to consider to implement your own resource provider.
This is another huge step toward a first BETA version of Diavolo.