If you have been wondering about status for the transition to mozbuild as a replacement for makefile infrastructure, a source is becoming available. People involved with the conversion have been meeting bi-weekly on the topic – details and content can be found in etherpad meeting notes:
Currently an effort is underway to begin bulk porting makefile variables over to moz.build to help finalize this portion of the transition. As makfile variables are converted advanced notice will be given before the changes go live. Also examples will likely be provided to document syntax needed for adding new content.
Stats are being gathered for amount of effort required to convert individual variables. Bugs are being opened to track conversion of individual variables and after being digested a bit more a summary page will be maintained to allow viewing state of conversion progress at a glance.