Firebug has an invaluable feature: the ability to navigate and explore the global scope without setting a breakpoint. It is placed "front and center" on the UI and is easy to find under the "DOM" tab.. I'm not aware that the Web Inspector has a feature like this; if it does - it's not easy to find.
You can do it in the inspector by typing "window" in the console. We think that is how most developers inspect DOM objects and likely wont dedicate UI space for this.
Yeah, you can type "window" in the console, but the output you get is not "live". For instance, if you type window.myAwesomeVariable = "Hello Webkit"; You don't see this new variable appear as you created it - in the object shown in the console log. That makes sense not to show it in the log, because tracking the live state of an object in the log would ruin the purpose of having a log... Having a view where you can watch stuff change live without needing a breakpoint would be great. I don't think Firebug even has this ability (I think you have to "refresh" the dom tab by clicking away and then back to it - to see updates)