Questions have been asked of whether twitter could scale if it really hits the mainstream, when, say, top celebrities joined and are followed by their fans, and twitter has to serve all these updates from these celebrities to all their fans.  Could that day be the end of twitter ?

In any case, perhaps it will be a good thing…. For once perhaps people, including myself, would stop tinkering with their mobile phones… then again there are lots of other social network types of apps to keep us busy on our mobile phones..