Wait as second? A fad? Well, only time will tell if that's the case. Currently (to me at least), it seems like Twitter is yet another channel for social communication between multiple parties. If you think in terms of RSS, with a 140 character limit - (some times it's better if some people talk less*) -, you simply have the same selective personal input with.some useful conventions providing some uniquely new levels of information access.
So, when it comes to cutting edge, would you expect any less from Drupal? Of course not. While there are a few twitter modules on Drupal.org, I chose to focus on the Twitter module created by James Walker (walkah) of Lullabot fame.