vars merging

Hi,

I'd like to have a default vars files with a number of complex YAML objects, and then allow
users to come in and define their own YAML files that are merged on top of the existing YAML
objects. At present Ansible behavior is that the top level object is overriden- is there any
capability or technique I can adopt to use one vars to supplement an existing vars?

first.vars:

ATM this is AFAIK not possible, but

+1 for me, I have some use cases where this would be nice to have.

Serge