Thats the problem right there kellog. Scalability sucks on these systems.
I would say the main impediment to adoption of these systems is the confusion about the technology. Even how to elaborate on that statement has me wondering.
An example: Trimble uses 900mhz for my basestation. Topcon comes in and explains why thier 450 mhz base is better, cheaper, more functional etc. But in the end, they both do the same job. It is very confusing for people to understand how two companies come up with two seemingly completely different solutions, using completely different hardware configurations to do the same thing.
Right now, there is no standardization between brands, no standardization between hardware, or software for that matter. Every company does it thier own way. Some work better than others.
Back to scalability, a laser and a stickman will cost around 10k. But to get the machine to do what the stickman does, you have to add another 140k to that. So everyone looks for a system that you can adopt in stages. Companies have responded by creating a hodgpodge of bits and pieces that do a little bit of the task without doing anything well.
I own an ag gps system, several hand held systems, laser grading systems, and machine control system. I have a detailed working knowledge of the whole range of function. Yet, when i walk into a booth at a trade show i can still be dumbfounded by the range of products available, and how they all work together.
I think that in order to improve adoption of this technology, there needs to be a couple things happen. The systems need to mature. The GPS signals are standardized, but the correction signals are still changing and improving. Until they settle down, confusion will reign.
Also, and more importantly, users need to be educated about what exactly the systems will do, and how they do it. Wikipedia has some excellent info on GPS.
http://en.wikipedia.org/wiki/Gps gives a very detailed history of the development of the gps system. It gets pretty crazy technical near the end, but the first part is pretty layman. Very good reading for someone trying to learn the basics.
Lastly, more people on the project design end need to be able to code the data files. Right now, adoption of gps grade control is limited to large projects. This is simply because the projects are large enough to justify the investment in training and tools to be able to produce the data files. It takes a ton of training to get good at that end of the system. It can only be done as an in house system right now, where the person who pays for the tools etc, gets to keep the payback.
Once a person understands how the system works, what components do what, it becomes self-evident where the money needs to go, and exactly how the system can make you money.
Personally, i can't wait.