Of course i need a phone, but its not really important to me as currently i'm using an old crappy nokia.
I currently have a Macbook Pro i7. So really, the word "portability" may, or may not be that impotent, as the Macbook pro is portable, just not AS light as the Air.
In that case, get an iPhone. What are you gonna do with two laptops?
OK, provided you don't need both laptops, I'll assume that you're going to sell the MBP, which would still allow you to break even which would still allow you to get the 4S.
I was basically going to go for MBA, selling my Macbook Pro for it. But, ya since i already have a Mac, not quite as portable as the air, MBP will do for a few weeks.