The module shows signs of maintenance, ie a release history ...
I really like to check a module's changelog looking particularly for this:
evidence that input from others has helped improve the quality and/or feature set of the module
I see this as a direct reflection that:
people are using the module and pleased enough to want to improve it
the module author cares enough about the module to respond well (even to ego bumps)
the module is evolving into a better implementation under the best testing - use in the real world
In the absence of a maillist archive for the module the changelog is a view into how well the module/author/user has succeeded in the real world. This helps me feel good about how well it will succeed in my world.