Audi has already adjusted production of new A4s to eliminate the software glitch. Meanwhile, the German manufacturer was quick to emphasize that Takata did not manufacture the affected airbags.
According to Reuters, 250,000 of the affected A4s were built for the Chinese market, while another 150,000 were sold in Germany. Audi didn't provide a breakdown beyond those two countries, although it'd be a surprise if there weren't at least some affected airbags in the US market.
We're still waiting on official word of the recall from Audi or the National Highway Traffic Safety Administration. As soon as that's available, we'll be sure to update this post.
UPDATE: We've reached out to Audi USA for additional information on the recall. According to spokesman Brad Stertz, roughly 101,900 of the 850,000 vehicles being recalled are in the US market, all of which were built between November 2011 and October 2014. Both dealers and NHTSA were informed of the recall yesterday, while repairs are slated to kick off in November. The 20-minute repair will see techs "perform an adjustment to the airbag control unit deployment parameter." There have been no reports of accidents or injuries in the US market.