internet - the newest trend: metroblogging

I'm not really looking for another brilliant idea to make my life even more busier, next to the China Wage Indicator, Chinabiz, the Connecting China project and some other smaller activities. But metroblogging is the trend, London has it, Chicago has it and very soon Tokyo will also have it. And they work already together. So why should Hong Kong, Beijing and especially Shanghai not have it.
Wang Jianshuo is already doing a good job, and he has been playing with a similar idea. Why is not just somebody getting things done?