This is totally cosmetic, but thought I'd ask...
In the past I've usually seen the extension .yaml, but all the examples and tests in ansible use ".yml". Funnily enough there is one .yaml file, the YAML documentation. I've looked it up and found:
http://www.yaml.org/faq.html
Is there an official extension for YAML files?
Please use ".yaml" when possible.
Any reason for having picked .yml?