Back in October, not long after Ice Cream Sandwich was unveiled, Google made noises about its latest Android operating system coming to its former flagship phone, the Google Nexus S. Since then, we've heard nothing. Until now, that is.According to the Android Police site, Google is currently testing the new operating system on the Nexus S. Not in the sense of someone in a white coat in a lab testing. Oh no, something far more widespread – it is 'dogfooding' the upgrade.No, we've never heard of the term before either. Apparently, it's a tech industry term relating to employees using products before they get released to the public. Which is what Google staff are doing right now. Playing with the Nexus S and Ice Cream Sandwich to spot any possible bugs in a 'contained' environment before the company rolls out the update to the wider public.The details came to light after some employees shared their experience via Twitter and Google+. One employee, Adel Saoud, wrote: 'Just got Ice Cream Sandwich update on my Nexus S & it's looking great ;)'. However, he did add that it was 'an early one for Google employees so we test it further'.All of which begs the question of just when the finished ICS will roll out for the Nexus S. Speculation is that the upgrade could be ready in just a few weeks. But with Christmas and the new year celebrations coming up, early in 2012 would perhaps be a better bet.