WHMCS and Prosites Domain Registration 2014


I've spent 20 minutes reading up on where WHMCS and Prosites integration is at and I'm still confused.

When someone wants to register a new site (either from new account rego form or from somewhere in the backend?) can they register a domain from my wordpress install?

Which registrars are currently available? eNom, etc.

When will the other domain resellers be added?

Is the above happening in Prosites, WHMCS integration or WHMCS provisioning plugin?