It's still "water cooler talk." Most people who work in offices still work in physical offices. So the water cooler wouldn't be replaced, just what's discussed there. And this still tends to be popular TV shows, celebrity news, etc. -- all things that are going online.

If I am correct the term "Water Cooler Talk" had to do with idle gossip, in the olden days, The only equvilant I think might apply nowadays is the tweets on twitter. The short blip type posts are a perfect medium for spreading nearly anything quickly, without the need for verification, stating sources and little to no censorship. Recent news of how twitter was used in media controlled middle eastern countries to convey news, to those who's governments tried to repress free speach and media coverage was a great example of the good "Twitter" can do (depending on your viewpoint). But those kinds of stories are only the positive public relations side of the coin. As with most things there are two sides to the coin. The negative side isn't publically reported, as often, unless the story reaches a point of legal actions. With any sort of mass distributable form of communication, the many, smaller hurts or injuries from idle talk, gossip or "Water Cooler Talk" generally do not come to the publics eye in the light of day. This doesnt take away the sting of the person spoken ill of, negatively about or embarrassed via the internet, where many persons feel safe behind thier monitors to act in ways which they would not in person.

Honestly, I don't think there is a new term. much like "hang up the phone" (we rarely ever hang it on anything anymore, its all mobile) it is just a term that has endured the times and I think will become timeless. I have no reason or backing behind this besides my personal beliefs and what I observe.

ENGLISH, WE SPEAK ENGLISH