Very cool! I was always struggling during live presentations switching from browser to console window. Now I can use a browser window on the projector screen for both presentation and console.
Not to be snarky, but what's wrong with Alt+Tab (Or platform-specific equivalent)? You still have to use multiple windows -- that both happen to be in the browser doesn't seem particularly important.
Ideally, you could even have console demos "embedded" within the presentation itself, perhaps even multiple consoles in order to show how changing state in one system affects another system.
You would need to set up gotty ahead of time with the specific demos, and embed requests for those iframes in slides or parts of slides.