Vodafone Australia has announced that its version of the Nexus S will be getting an over-the-air update to Android 4.1 on July 19th, which may also signal an international rollout for GSM models at the same time. While Google's last Nexus S update saw a concerted international release, some variants received the update after quite a noticeable delay.
Vodafone's blog also says Samsung is "prepping" the Galaxy Nexus Android 4.1 update for submission to the testing process, so the Nexus S might just beat the the Galaxy Nexus to the Jelly Bean finish line on Vodafone's network this time around.