What's with the EntityXY framework? I look at this, while implementing my framework, the system manager is greatly the same.
But my question to the post of crancran remains, could the message queue for moving the entities combined with an event manager which I need anyway?
The reason you find so many variants of an entity framework is because there is no standard practice.
As for the queue, you could implement a single or multiple queues depending on your needs. Chances are a single queue would be sufficient as a starting point and build upon that idea long-term if you find you need to separate the queues for any particular reason.