I don't think cloud hosting will reach it's panacea until I can just upload a site or application, and be billed for what I use. No calculators, or intervention needed. Are weekends slow? It automatically drops a node. Get front page of Hacker News? Scales up automatically. Hosting that "just works".
The adding a node or dropping a node isn't really a problem. The problem is that most applications can't handle that type of environment. So until all applications are written in a way that can handle that, don't hold your breath.
