Surface 2 had a whole new case, so they decided to upgrade some things across the board. Surface Pro has the same case, therefore nothing internal was changed either. It is a shame... but as Jeff will probably pop up and say soon, the Surface 2 is their focus and 'main' projectSurface Pro 2 was simply made because they could.
Sorry but I can't understand this thinking! I think that a 3.5MP camera costs to them few cents more than the one installed... If I make a hi level device I will provide better hardware than the entry level, specially if this hardware has a ridiculous extra charge