Why? Because many people will reject Anarcho-Capitalism and as such it will have to be enforced, through a State, the same problem Lenin and the Bolsheviks ran into. And once you start doing that... you make enemies and you need to protect a central hub (State) so it hires security (Soldiers/Law Enforcement) and then you're right back where you started.
Possibly. It really all depends where the equilibrium for a state is. And right now (pre-bitcoin) the equilibrium appears to be a socialistic state. But once bitcoin becomes popular enough, that equilibrium could rapidly change. Just like freedom of press & speech via the internet is changing Syria, Egypt, Russia, etc. At the very least, bitcoin places huge restraints on government's control of currency. Worse case, people just stop paying their taxes. Will bitcoin dissolve governments to AnCap or smaller local governments? We'll just have to wait & see.