It was news to me, because I was looking for some kind of documentation for quite some time now. The best I found so far was webkit blog at http://webkit.org/blog/ In a nutshell, it's not about the tools, it's about the missing docs and I hope google invests more resources into teaching the developer how to use these tools more efectively.

Dev tools is an excellent tool for web developers, and as far as I know, no one is using it because of Firefox and Firebug. I'm not saying they aren't good tools: they are. It's just that I personally prefer Chrome over Firefox as a browser, and I'm really glad I found this documentation resource.