Just to chip in, I've looked for something like this as well.
We have some specific needs for yum that the current yum module doesn't quite provide (downgrade, exact version upgrade)
My choices were:
1) Write our own proprietary localyum module and maintain it ourself (use current yum as a reference)
2) Enhance ansible's yum, and lobby to have our changes/enhancements accepted
3) Try to express our incremental needs in Ansible itself, i.e. use Ansible's yum, surround it with just enough Ansible logic to achieve our needs
1) is a fair amount of effort given how comprehensive Ansible's yum already is. It will be relatively high maintenance, and fails to leverage Ansible's yum (or entails keeping constant tabs on Ansible's yum on a regular basis to down-merge)
2) Our needs may not align with the community's needs
3) is the path I experimented with, but Ansible is expressly not Python, so it's cumbersome to express decision/logic
Long story short, an Option 4) "Ability to write a new module that uses an existing module" would have helped.