Hi Adrià & Stefan,
The Dataset Exchange WG within the W3C has just released a final Editors Draft of “Content Negotiation by Profile” . This specification describes how to negotiate for content according to profiles, rather than say by format or language. The Dataset Exchange WG is also responsible for the revised version of DCAT  which is also in final Editor’s Draft stage.
For the last W3C standards process, it’s important for implementations of standards to be noted and tested. I’m keen for CKAN to support Conneg by P as much as possible both to demonstrate an implementation of that specification but also so that CKAN implementors can get their content out according to old and new versions of DCAT.
I think that the ckan-dcat plugin’s most of the way there – the fact that new profiles can be defined by users and used to export data etc. – so the only real work is to ensure that the API matches the new Conneg spec. This situation – that there’s a system that actually can do all the things Conneg by P’s talking about but which is using an existing API that’s not aligned – was anticipated by us, the Conneg by P editors, and now we’re keen to test out retrofitting the API to an existing system.
If I was to start work on enhancing ckan-dcat to work as per Conneg by P, would either of you two be available over the next 6 weeks to review the enhancements? I’ll be exiting the extended version on a CKAN catalogue that I’m using day-to-day for the Geological Survey of Queensland in Australia .