Honestly! we have no idea what Apple has in store for us this year but at least thanks a bunch of leaked photos of the next generation iPhone, we are quite sure that the new iPhone will have a brand new casing.
Graham, over at Mac Predictions, has taken his imagination to the next level by creating some mockup images for the 3rd Generation iPhone.
Here is one with a textured back and metallic borders.
Click on image to enlarge
And one complimented by a black metallic bezel on the front.
Click on image to enlarge
Though these mockups do not give any significant information about to the features of the new iPhone, they still give an idea about the looks and the color.
If one of these mockups really turns up to be as the new iPhone, I would vote for the second phone.