No way. Bigger does not mean better. There are absolutely people who'd love a 6" phone but there are most certainly people who want something smaller than 5". There's no way they'd make the smallest phone on the market 5". Just my $.02... but seriously.
I could easily see 6-7" being fine. Additionally, I'd love it if they increased phone size by also going back to a 3:2 ratio (or maybe even 4:3). Get back away from this skinny vertical phone and also have some horizontal width.
No way. Bigger does not mean better. There are absolutely people who'd love a 6" phone but there are most certainly people who want something smaller than 5". There's no way they'd make the smallest phone on the market 5". Just my $.02... but seriously.
I hope the next 3 - 4 years Apple gives us three options (5.5' , 4.7' , and 3.5 - 4'), as not everyone likes being forced into a particular screen size.
I think the screen size will get bigger but not the phone. As the bezels shrink the will increase the screen size to fill in the gap. At some point they will figure out the tech to get touchid built into the screen allowing them to drastically reduce the bezels. That may well be several years down the road though.