Is there any public iOS 8 API available to implement 3D flyover or at least 3D view as shown on Apple Maps App screenshot below?
In order to achieve what you want, you have to play with the camera. You'll have to update the pitch, heading, and altitude if needed.
Have a look here, you'll find everything : MKMapCamera Class Reference
Update : Unfortunately, you can't pitch maps who are satellite or hybrid.
If the map type is MKMapTypeSatellite or MKMapTypeHybrid, the pitch value is clamped to 0.