The French mobile site, SFR, has an interesting "roadmap". According to the pic above, the Samsung Galaxy Nexus and the Nexus S will be getting a new version of Android 4.0/Ice Cream Sandwich, version 4.0.5, as early as March. Interestingly, the chart also exposes that the Galaxy SII will be getting its first ICS update sometime the same month, alongside the HTC Sensation. For now we will chock this one up as a rumor, but it seems like a decent possibility.
Source: SFR