Ford had exclusive rights to "SYNC" for a period of time. That period is over, and then other companies could use it (or at very least the base platform). But the "SYNC" brand name is still Ford-owned.
In some ways, that's why you're starting to see the branding of "MyFord/MyLincoln Touch" on the newer vehicles -- Ford is starting to promote the other features based off of SYNC; however, SYNC and Microsoft's base platform is still there.
OnStar's longevity will really depend on how well it will keep up. I think Ford actually got it right in their implementation, and I'm a bit skeptical that software developers would be willing to adapt whatever applications they have just for one system (OnStar) versus a general platform (like Microsoft Auto) that can be used by owners of Ford and other auto companies.
Kia was recently advertising its Sportage with the Microsoft technology. The way it was described in the ad it was clear that it sounded exactly like MySync. I'm sure in a few years, the majority of new cars will have similar technology.