What's missing is consistent deployment and infrastructure support. There are cryptographic algorithms that work just fine. Management is a similar story. People are starting to realize that having a consistent management framework is important. As more technology gets deployed, we don't all want to turn into network administrators.
Agents are one possible approach to management, but there are others.
You already find Hewlett-Packard Co. and IBM Tivoli Systems Inc. putting out management applications that have a great deal of visibility into what they manage. Those applications don't use agent technology. They use a consistent set of interfaces. Some emerging technologies use client-side resources and logic to increase an application's availability and reliability. The vendors delivering highly reliable servers today talk about making servers that never crash or about linking together a set of servers so they never break.