If you are interested, the Meta bug is here
There are a number of followup bugs that need to be addressed, the list is here:
There is a lot of work to do yet, including some platform work. Two glaring bugs are:
The existing errorConsole in Firefox has messages sent to it that do not know what tab the error originated in. We really want to isolate all messages you see to the tab you care about as a web developer. It becomes tedious to try and watch the scrolling messages at times if a “noisy” page is loaded in one of your 200 open tabs. So you will notice that not all errors are displayed in the console.
In Firefox, images are loaded differently than script, css and html pages, so much so, that it is difficult to trace these image loads back to the originating tab as well.
Once these two bugs are fixed, your console messages will be very accurately focused to the tab you care about.
The console itself has the standard API: console.log, console.info, console.warn and console.error.
This initial landing into Minefield nightly will hopefully generate some valuable feedback from web developers and Mozilla developers alike. Please do not hesitate to comment here or even better in bugzilla.