Event loop introspection

[Mark Miller's thesis](http://erights.org/talks/thesis/markm-thesis.pdf) contains a picture (page 107 of the document, Figure 14.2) of an E Vat which is somehow the equivalent of a JavaScript WebWorker. The context a webpage runs in is a vat.
A vat is made of a queue of "pending messages" which is what in the JavaScript world is called the event loop.
It would be great if it was possible to inspect, represent (and why not dynamically interact with) the event loop and the list of pending messages, very much like we currently can mess with the call stack.