The Internet was built on only a few rules, but one of them was "keep the network dumb and the end points smart." That means that networks are designed to know little about what they're carrying, pushing the onus of consistency checking and packet handling to the server and the clients. That architecture has served the Internet and private networks very well in the roughly 30 years since the advent of TCP/IP. In the next 30, it's going to change -- big time.
Gradually, the network has gotten smarter. Quality of service, firewalls, and layer-3 switches have all enhanced the security and speeds of local and wide-area networking. Today, the rapid pace of development in solid-state storage and low-power, high-speed CPUs is truly changing the game. It's possible to inspect every packet between gigabit interfaces and make intelligent decisions on whether the communication should take place or what direction the traffic should be routed -- all at wire speed.
Next up: Networks will become smarter than the client. Advances in virtualization and thin-client technology are reducing the processing power present at the client side, just as switches and routers are gaining smarts and speed. More and more server tasks will move into the network space, running on core switches. Desktop systems will disappear in favor of monitors with an Ethernet connection, and servers will return to their mainframe roots, offering little more than storage and a hypervisor layer for a few applications. After all, what do you think made George Orwell's telescreens so ubiquitous?