If they make it right, I think a 6 incher would be nice. Phones arent really phones anymore. Voice communication have taken a backseat. They are more communication/productivity devices. I know atleast for myself, I barely talk on my phone at all, but im always using it for text, instagram, twitter, photos, video, editing, web, games, e-mail, etc. Its just the evolution of technology. PC/laptop sales are slowing, as smartphone sales are picking up, because they are an always accesible computing device, not just a phone as they used to be. People always uses the "too large to hold up to my head" line with the Note series, but most people rarely even do that anymore for more than a rare 45 second call nowadays. I remember when the HTC HD was the first to come out and push the size limit with its 3.8" screen, and then the HD2 came out at 4.3" and people thought it was HUGE. People thought HTC was insane, and that it wouldnt be pocketable or useable. Now 4.3" is the minimum/standard for even the lowest of good smartphones (outside of the iPhone). Its just evolution.
Obviously it wont be everyone's cup of tea, but looking at it in that guy's hand, it doesnt really seem that bad.
And the Note III is rumored to be 6.3"....