Obviously, it has a long ways to go. Hijacking TCP sessions would be a nontrivial exercise and would mostly fail. We are a long ways from widespread opportunistic IPSec usage. However, in many environments IPSec can be deployed and would help. Deploying it properly and maintaining it is left as an exercise to the reader.
Many attacks come from internal sources.
The difficulty in gaining some sort of access is negated by the simple fact that the attacker already has legitimate access. Good security should be hard to disable or misuse. Security software should aim for this level of user ease and safety. Inc. All rights reserved.