Currently domains and SSL certs are the only areas that have the extended functionality in terms of tracking, but eventually I would like to set most sections up like the domains and SSL certs are currently. Basically, anything that could have a cost, whether it's web hosting, email hosting, DNS services, etc., you would be able to track that in DomainMOD along with its cost and other details. And the next phase after that would be the ability to interact with all of those services directly through DomainMOD, so you could create/delete email addresses, manage DNS records, and so on.
It may still be a while, but that's the eventual plan for the software. Your one-stop shop for managing all of your hosting resources.