TUAW reports that has Apple has begun allowing developers of App Store applications carrying mature (age 17+) ratings to issue promo codes for the applications. The move apparently comes about a week after Apple's restriction preventing issuance of promo codes for such applications began gaining attention.
Luckily, it seems that Apple has been listening: over the past few days, we have received word from a number of developers stating that they are now able to request promo codes for their 17+ apps. While Apple has not made any official comment on the issue, it appears that they have quietly conceded this battle to the developers, once again enabling them to distribute promo codes as needed for all of their apps.
Apple's promo code policy for 17+ applications appeared to be related to a lack of parental controls applying to promo code redemption. At this time, it is unclear whether Apple has made any technical changes to the App Store to address this issue or if it is simply a policy change.