to all those monkeys here that do not understand the needs of others. Just cause you don't need 17" screen as you can use your 13" with external monitor doesn't mean that we all have the same option! For crying out loud if I could always connect the external screen then why would I even bother with a laptop? I could get mac pro and get all the power I need and have all the screen space I want with as many screens as I need!
To me, 13" is ridiculous computer. Too small to do anything yet I don't come here bashing everyone around just cause your model sells more! There is a lot of people asking for 17" and those people ask for a reason. They don't invent their desire and they do have needs for it so why do you keep coming and bashing them for it? I want and need 17" for the screen estate. I have 15" and its just damn small. No, I can't plug in external screen everywhere I go! If I was like everyone of you then I would be coming here and saying that I hope they will discontinue 13" and 15" so you can all use fricking 11" MBA! Now lets see how you would like that when your NEED is different!!!
For crying out loud, leave the people alone. There are people that actually need 17" for a valid reason so stop attacking them! Be understanding that there is a group of people that have different needs than you! Yes, 13" is fine for facebook but those that need 17" are in a different software group. In fact, try to do anything in Maya on 15" for extensive period of time and let me know how that goes. Having just graph editor, hypershade, outliner and perspective view + shot view open. Then come here and boast how great the 13 or 15" is great for anyone!