The Producers Guild of America does this every year: prior to announcing the nominees in their other categories, they release those for their Documentary category, only without citations for eligible producers. Rest assured, they probably won't have confirmed them even when they announce their winners. Such is their wont, apparently. Those winners will be revealed on 25 February; nominations for other awards on 12 January.
Outstanding Producer of Documentary Motion Pictures
All That Breathes
Fire of Love