We don't have to put the data in any particular format. There's no need to choose any format. We can have them all. With whatever I do, I want to support everything.
If the CPAN client says it can handle JSON, it can download JSON. If it wants YAML, it can download YAML. If it needs just text, that's fine too. SQLite? Excel? XML? Oracle dump file? ROT13 ASCII art? Bikeshed Standard Protocol Specification Hex Color Expanded Multidimensional Language Storage Format Second Edition? No problem. At the application level, there will be something that says "Give me what I need for module Foo". Beyond that, it's just data connectors. If we do it right, almost none of the code should care or know the format. On the server side, we can have as many formats as Andreas cares to make for us. After all, it's his database that is the actual source of the data.
