GPS fails, what happens to security?

I'm sure many of you saw this story, about the GPS system potentially failing, come across various news wires, though it hasn't yet really hit the mainstream. And maybe it's much ado about nothing. The GAO is sort of famous for warning that things are going to happen, but then they don't happen by virtue of the strenuous warning that was issued. But here's how Information Week puts it:
The global positioning system could fail next year and repairs aren't moving quickly enough to prevent failure, according a report from the U.S. Government Accountability Office. It's unclear whether the U.S. Air Force will be able to acquire new satellites in time to prevent disruption in GPS service for military and civilian users, according to the report.
So, I'm thinking that could be bad, if GPS systems just stopped working all of a sudden. I've got a call in to confirm this, but I'm pretty sure that StarTrac service that Centra-Larm puts out would just stop working, leaving a lot of customers pretty angry and drying up some serious RMR. And that's just one very small example. Guardian Mobile would certainly be hosed, as well. Here's what their head honcho told us:
John Tedesco, president and chief executive officer of Guardian, said, "Marketing up to this point has been done primarily via word of mouth, but we've gotten some early adopters. Now that GPS is mainstream and there are exciting new products, we need to market to the industry and let it know that we are the leading provider," said Tedesco.
That's right, GPS is now mainstream: In your iPhones, Blackberries, and, yes, a bunch of security products. Is this a big deal? It seems like it could be. More from Information Week:
"If the Air Force does not meet its schedule goals for development of GPS IIIA satellites, there will be an increased likelihood that in 2010, as old satellites begin to fail, the overall GPS constellation will fall below the number of satellites required to provide the level of GPS service that the U.S. government commits to."
So, maybe not a widespread black-out of GPS, but spotty and intermittent service? That might be almost as bad. Those security applications pretty much have to be up and running all the time or they're not much good.