This is the latest rumor on the web right now. If it happens, it is great news for Apple and the users of their iOS devices. But the loser would be the open source community.
Apple would most likely kill the app on competing platforms. It might get killed on iOS devices too with apple integrating their tech and data on their own mapping platform.
Waze is largely an open source project. I am not sure what kind of licensing they have. Apple of course would only acquire them if they can use the same data on their own platform which is of course not an open source project.
Waze disappearing from the market would be a major blow to newer mobile platforms that are expected to arrive in the market this year.
Sailfish is one. Tizen is another. Mozilla Firefox OS is probably sticking with mobile web apps. Ubuntu has just announced their own mobile OS. These platforms would need a solid GPS Navigation app like Waze. They would have to look at other alternatives.