App Store promo codes, the codes which allow any developer to issue members of the press with copies of their application for review purposes and were previously only available to redeem by those who owned or who had access to an iTunes U.S. account, have today gone worldwide.
As a result of this, the way in which promo codes in iTunes Connect are accessed has changed - you now need to load your 'version information' in iTunes Connect to request a 'Promo Code'.