The possibilities of this thing blow my mind. Very cool idea.
As much as I want to like Pharo and am amazed by its fast progress, its integration story (to external data source like PostgreSQL) is pretty weak, currently. I'll be tracking the progress of this project to see how it goes, though I've yet to love Clojure.
I want to add that I think it's a beautiful approach to solving the problem; rather than implementing a complicated mechanism for interrogating the application state from a tool running in another process, the author is flipping that around and putting the editor inside application so that it has a very simple access to the application state. Love it.
One of the harder issues when I'm building microservices is stringing each service and dependency together and debugging. With this I could put together a full staging environment and log into each service to monitor and tweak problems I've found.
2. Limited hardware or access.
This is important because it's talking with Java Clojure not Clojurescript. Because it's entirely browser based, I could spin up an EC2 instance and load the editor on my phone. I can't do that with a regular Clojure environment in my phone.
IIRC, it does support connecting to a remote REPL like this.