It's interesting - and occasionally terrifying - to see what's happening in the Web2.0-Social Media-Cloud Computing world. There are many startups trying to be the next Google, the next Flickr, the next Reddit - but they are actually trying to become the next Yahoo, and of course they often don't make it. The reason might be that it's not really possible what will be the next big thing, but it's pretty easy to see what is the previous big thing.