When and what can we expect from the next Macbook generation?

So right now I am really curious how Apple is going to differentiate itself from the ''ultrabook hype'' that is going on in the industry right now. What can we expect from the next generation of Macbooks Air and Pro models? Is Retina going to be a stock option? Will the next models feature touchscreens and/or new technologies? And most importantly; when can we expect the next generation of Macbooks to hit the store shelves?

I am really curious about your opinion about this you guys.