The point is very very very rarely you actually hear of hacking stories where someone has actually "guessed" a password. Most of the time it's either social hacking or a db dump. Password choice is important to avoid password reuse but I am pretty confident that password guessing is a hugely overestimated risk.
The News of the World scandal going on now is, to some extent, about guessing the password. However, they were guessing passwords like 0000, which probably isn't quite what you had in mind.
