This. I like not having to change my grip to access all of the screen with one hand. I'm not willing to trade that for a bigger screen so hopefully the 6 will at least have a 4 in variant.
One handed use is still very possible with a larger screen and a larger device. (Apple seems to think the iPad Mini can be used one handed. They say so in their promotional video for the Mini.)
Also, even if a screen is harder to use one handed, there can be clever solutions:
http://www.androidauthority.com/note-3-one-handed-operation-how-to-280458/
If Samsung can figure out a way to offer a larger screen while still giving people the ability to use it one handed when they need to, can't Apple?
If Motorola can fit a larger screen into a smaller body (ala the Moto X) using edge to edge design, can't Apple? Try handling the Moto X just to feel it; it's amazingly comfortable to use one handed.
I would be disappointed if the iPhone 6 didn't come with a larger screen. I think it's time, Apple. Some might even argue it's overdue.