quad core come on i think my corrections are a bit more realistic
Its totally possible, the implementation of mobile processor is nothing like a desktop quad core, but I'm not going to recap that for you.
You're probably right about the baseline model being the same VR chip as in the iPhone 3G, but the higher end model will definitely feature a dual core if they make any significant hardware improvements, which they will, else no reason for a new model.
Definitely a dual core on the way. Quad core, maybe next year, or debut in an iPod touch.