Along side the new Google maps app released into the Apple app store, developers can now also use the same mapping Google Map SDK in their iOS mapping apps, as an alternative to the sometimes flawed native Apple maps SDK.
The new SDK has a feature rich set that is missing from Apple's mapping solution such as super-fast vector mapping, new layers, and more. Developers can also change the Google maps view to include information such as traffic conditions, and control camera positions in 3D. And finally URL Schemes are built into the SDK which means you can link directly to the Google maps app if users have it installed on their device.
Initially some developers questioned why Google would release their new baby to iOS developers and not covet it on Android, but it's obvious Google wants to be everywhere - and despite the continuing disputes between Google and Apple, that still means the developers IDE as well :)