At the recent Nokia Go Play event, when questioned about a forthcoming user interface and its similarities with the Apple iPhone, Anssi Vanjoki, Executive VP Multimedia at Nokia, responded "if their is something good in the world, we copy with pride".
This surprised many and has resulted in some negative comment, most likely as Nokia have always been revered, as the first mobile manufacturer to develop their brand, through a consistent and "easy to use" interface.
What we must remember, is that even though the user interface is the brand, it still must function within some expected norms, that enable ease of use and speed of learning. Take the traditional mobile phone. The numeric keys are (almost always) laid out in the same 3 x4 grid. Nobody complains about this, as it is an expected norm.
The challenge for Nokia, will be not be to see how closely they can copy the Apple user interface, but to identify the norms and still bring their own flair and innovation, to enhance the overall user experience.