Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
As someone who bought the 20" behemoth that is the HP Dragon HDX laptop, I'd be quite happy with a larger MacBook. :)

I found the 13" 2011 MBA that I used to be a little too small for my taste. I've recently got the 15" rMBP and would be quite happy if it were a bit larger.
 
This. The more I get used to larger screens on the desktop, the harder it is to use small laptop displays like the one in my 11" MBA, which I bought because of its small size and weight. But if someone came up with a foldable 20" screen, I'd go for it in a heartbeat.

I think that will happen. had a best buy associate tell me a Samsung rep brought in a device that folded like a price of paper. it then unfolds and snaps into a solid screen the size of a tablet
 
Anything under 15" is too small to me. I wouldn't mind a 17". I have a 2007 MBP that I hook up to a 27" external monitor. Getting close to getting the latest and greatest MBP, 15" with 16GB.
 
17" is too unwieldy. At that point it might not be "heavy", but it's very large, bulky, difficult to maneuver. 15" is just kinda the perfect zone, IMO. 13" is the size you get if you NEED a small machine.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.