Dude, you are dreaming if you think Apple will put 2 cameras on the next generation iPod Touch. Apple is very cunning in the way it handles features on substitute products (i.e., iPhone and iPod Touch). If they were to put 2 cameras and a retina display on the iPod Touch, it would take away from iPhone 4 sales IN A HUGE WAY. The front-facing camera and retina display ARE the iPhone 4. People are buying the iPhone 4 because of the retina display and the front-facing camera, giving them the ability to video chat (Facetime).
Next generation iPod Touch will have ONE camera, if that. Let me assure you, it will not be front-facing.
Better resolution is a definite, but going as far to say the retina display will be there. Well, that's a stretch due to the fact that it is currently very, very expensive.