I think Dale is spot on in this statement and will take it a step further.
"Here is the big leap in logic . . . perhaps products and services for SCADA security are going to have to come from the control system software and hardware vendors, not the IT security market. This has its own challenges because doing security right is very difficult and not a skill set found in most control system vendors. Verano, MTL, Honeywell and others are starting down this path."
I think that the security of SCADA systems can be made into a key marketing differentiator for SCADA vendors. In some ways it already is. Their clients are certainly factoring it into their purchasing decisions. It just hasn't made the leap to vendors using it in their value add proposition or ROI. If you take the concept a step further it could be an easy profit margin enhancement area if played properly.
This is where I think IT side security vendors are missing out. There is significantly more cost tolerance in the PCN/SCADA world if you can show value than in the standard IT world. Standard IT security vendors that team up with SCADA vendors will have a significant new market that they can let someone else sell for them and probably at larger margins.
Eric is at the edge of this play right now and even doing it in a safe manner.
The SCADA vendors I mentioned here are the ones that are already noticing the benefits of differentiation.