The new iPhone 3G S uses an incompatible graphics library from the previous phones. The iPhone 3G uses the OpenGL ES 1.1 library while the 3G S uses the OpenGL ES 2.0, and the two are not compatible as OpenGL ES 2.0 is a superset of 1.1. This was a deliberate decision by Khronos, so that it could make some large performance improvements. One of the biggest features is the addition of pixel shaders, which gives considerable flexibility in making 3D content. Both Jonathan Hirshon and Jon Peddie weigh in on why this move probably won't be a problem. Link to story in Japanese.