It seems like some people (eg #790948: How to reference a nodequeue from a node or user - query by Title? CCK?) have a need to reference a nodequeue from other objects. I too have this need (I would like to be able to create a node queue and link it to a specific entity which "owns" it). It seems like the best solution would be either:

1. Add a reference field type & widget that can be used to reference a nodequeue object. Other entities can then use this field to connect an entity with a nodequeue.
2. Alternatively, convert nodequeues into a proper entity. Then EntityReference can be used to link them together. As an added benefit, nodequeues can then also be fielded and translated using the existing systems for those elements.

Obviously #2 is a lot more work, but it seems like the more correct option in my mind. At the very least, some kind of reference field type that works to allow other entities to connect to nodequeues would be useful.