According to a couple of reports, (one from SFR in France, and one from Vodafone in Australia) The Google Nexus S was reportedly going to get Jelly Bean either today or tomorrow. This would lead to the logical conclusion that the newest Android 4.1 OS will make likely rollout globally within the next week or so. Unfortunately, it has been delayed by a regulatory hiccup and may not actually come out within the next couple of days. The report indicates that Android 4.1 "does not meet all Australian regulatory requirements related to emergency calls."
Of course, this could mean that it will only be delayed in Australia, but the good news referred from this is that it is functional and ready to roll.