Google won't dump their own maps for anyone else as long as they remain a competitive advantage. They're (thanks to recent events) clearly perceived as having some of the best maps in the business, as long as that remains so it's in their best interest to keep doing them in-house.
There's no need to dump Google's maps, these are wonderful in many respects.
They could complement their maps with OSM's data where it is better, and there are cases when it is. How such data would be licensed and what OSM should ask in return is an interesting question.
Technically and pragmatically speaking, tying in OSM data would be best for all involved. Politically, they wouldn't be able to claim the exclusivity they have now and they'd lose a giant bullet point vs. Apple (no matter how much OSM data they're actually using).
