I don't know much, but I don't understand Mozilla's effort to reimplement firebug natively. Right now their solution seems unusable and far beyond firebug.
Mozilla is just in an unfortunate situation, where Firebug's ground-breaking functionality was duplicated as a first-party feature of other browsers. So now as Chrome Inspector continues to add more and more deep functionality, Firebug is hampered both by being third party code and subsisting on Firefox's addon API.
