usergroups api module - any interest

I am looking to gauge interest in a usergroups api module. The module would be purely for developers to take advantage of in order to group users and then take actions on them. We currently are using this type of setup with a couple of different modules and run into this issue all of the time.

Backend/Defining groups:
Every user is part of multiple groups:
- they are part of the user group with their uid as the identifier (they are the only member of this group).
- they are part of a role group where the rid is the unique identifier for the group
- if you use organic groups, they are part of some group there.
- if they have posted a comment then they are part of the commenter group,
- If you collect profile information/address information, user's from a certain country or state is a group of people.
- etc, etc, Every user can be in any number of groups and the groups that are possible are pretty innumerable (extendable by API to create different group types).

Use cases:
- Say you create a view using the views module. One of the options is the access option and last I checked (in Drupal 6) you could say that a certain role could have access to the view, or someone with a certain permission. If you had the usergroups_api (and some views integration code), you could give everyone of a certain group access to the view.

- I recently developed the checklist module where you say that certain roles must complete a checklist. Instead of assigning a checklist to a role, it would be assigned to a group that must complete it.

My questions:
- Any interest?
- Is there anything like this already?