Great idea! I have a need for this right now and would love to see this implemented.
This would come in handy for me as well - have a need to run model action on page load, and like Pat said, running action on model query would cover that.
Up vote from me on this. We end up using a Snippet that runs on page load when we need some type of action to run. It would be great to do this declaratively on page load.