Last time we reported about it, the official Android 4.0 Ice Cream Sandwich update for the Sony Xperia S was supposed to arrive in "late May or early June the latest." Unfortunately, we're now seeing that there was a mistake in communicating the exact timeframe for the update. According to this post over at the Sony Mobile forums, the Xperia S will get Ice Cream Sandwich during the "later part of Q2." Most probably, this means sometime in late June. In any case, I really doubt we'll see the update rolling-out before the end of May.
Unwired View, Sony Xperia S Android 4.0 ICS update to arrive in 'the later part of Q2'