If you follow the 3D Robotics Twitter feed, you'll have seen that APM 2 production is underway again! The hard-to-get pressure sensors arrived, and shipments will begin again next week. At this point, the supply chain shortages should be over, so we expect APM 2 to be continually in stock once all the pre-orders are filled in a week or two. Yay!
(For the production gurus out there, be reassured that there is a layer of antistatic foam between each of those in-progress APM stacks in the picture)