LOL! I can't see myself laying on the couch with the 13"! I go for the iPad!...I can't see myself laying down on the couch with it propped on my lap like I like to do now with my 13". The screen real estate is nice though but not enough of an advantage to overcome the large form factor.
That said, I did compare the 13" with the 15" today @ Best Buy and while there's definitely an uptick in real estate, I still don't think it's big enough to comfortably work with two web pages + something else, or even just two windows...for something like that I think a minimum of a 20" monitor would be needed for my purposes...so I'm keeping the 13". Also, the 15" models seem to have a PWM backlight, so that's a nogo for me anyway.
Did you get your notebook yet?!