According to their source who has connections on both teams, Apple is using recruiters to lure away employees who were contracted to work on Google Maps. Apparently, a lot of employees started getting bored at Google when things attention to indoor mapping.
Many of my coworkers at Google Maps eventually left when their contracts ended or on their own accord. One guy looked around for other GIS work and ended up at Apple when a recruiter contacted him. He had heard rumors for a while that Apple was going to develop its own in-house mapping platform, and given his experience at Google, he was an easy hire. Apple went out of their way to bring him down to Cupertino and he's now paid hansomly as a GIS Analyst. Another coworker that was a project lead at Google Maps, left for the East Coast after his contract ended, and was recently contacted by an Apple recruiter. The position sounds like a product development manager position, and will pay him $85k+ and all the moving expenses from the East Coast. He's gone through 2 rounds of interview and seems like a frontrunner to land that position.
Notably, the source says that while it will be a tough road ahead, it is possible for Apple to produce a competitive product.
At Google Maps, we know what data's important, rendering priorities, keyword searches, and how the user experience is suppose to be. However, Apple needs to find a way to get its own 5 million miles of street view data, partner with the right folks, and spend a fortune on licensed data which it can.
Apple recently issued this statement following criticism over its new Maps app.