I do not know if there is a framework for this, but here is the idea.
Use the infinite scroll pattern from the wwdc idea and apply it to mapview. So, for example, use two types of map side by side (for endless scrolling along the X axis)
Usually one kind of map is displayed, but when dragging passes along the edges of the left / right, you can shift one type of map and move it to another image.
Your view dispatcher will need to add annotations to both maps, of course, and if you want to support any direction, this may mean that you need 4 kinds of maps to cover the corner case.
You can probably see mapview as scrollview when doing this endless scroll trick, as described in the wwdc 2011 scrollview session.
To synchronize both map displays, you need to transfer messages between the two, for example, with an increase. Not sure if the card has everything you need to watch these things, but take a look. You can use KVO to monitor an internal variable without breaking the Apple API check.
Good luck and let me know how this happens.