Mike Bacidore over at ControlDesign.com has written an insightful article discussing the recent shift of many of their readers from using traditional PLCs (Programmable Logic Controllers) to using more powerful PACs (Programmable Automation Controllers). I believe this points to an overall industry trend towards customers wanting robust and reliable systems which are more intelligent, and able to transfer data easily from device to device.
Mike also notes how a smaller number of his readers polled have shifted from PLC based control to PC-based solutions. I believe this indicates the potential for control system customers to switch to PC-based embedded systems, which have a cost and power savings over many PLCs.
Click the link here to read his article, PC-Based Controls Choice Still Evolving.