Seeing how the Note has been the absolute surprise hit of the year (and I was one of the posters who thought it would not do well at all. Ooops. Goes right next to my pick of San Antonio beating Oklahoma City in 5 games prediction....), a WP 8 style Note may well be a hit. But, I wouldn't be surprised to see this large of a phone not do as well if the market was flooded with them. Overall, 4.3" give or take .3 in either direction seems to be the best sizes.
Me? I actually want a 4.0" slider with a physical keyboard, or a 4.5" - 4.7" slab if no keyboard.
My wife? She would leap all over an over 5.0" WP. She was TICKED there was an Android bigger than her Titan. Still is....