Software buttons like on the Nexus are much easier to use one handed than the hardware buttons that Samsung puts at the very bottom of their phones. So if they do remove the hardware buttons it will actually be easier to use one handed.
Then whats the point of going to a 5in screen when the extra space is used for the soft keys.
Here is my wish list for the gs4
1.same size screen as gs3 but 1080P with a smaller shell
2.same layout buttons as gs3
3.stylus like the note but not make the cell have an uneven back so it lays flat.
4.micro sd slot and removable battery with around 2600mah
5.exynos 5 dual big little,we don't need quad A15s yet,2 a15s with 2 A7s and a tri core power vr gpu.
So make the footnote a little smaller than the current gs3 but make the sceen 1080p so people can use it a little better and keep the rest of the features the gs3 has now,I hope they don't get rid of the sd slot and stick to a removable battery.
Sticking with just 2 A15s would allow them to clock them higher also so imagine that phone running @2.1ghz full load and getting about a day battery life to boot.There is no 4 threaded apps and I don't even think android fully supports 4 threads or 4 cores yet and the video I posted with the guy trying to max the 4 a9 cores on the note 2 had like 7 flash videos playing at the same time and was hitting about 80% on all 4 cpus.
If Samsung times this right they can push a bunch of phones since there is no true 4 core A15 cell out yet and they can get this out in time before the ipone 5s and sell a crap load of them and then bust out the octo core with the note 3 and carry that over to the gs4 on a 22nm soc
edit pentile is fine also and I hope Samsung has a built in app that allows the user to adjust the colors,its not the screens fault its over saturated its how Samsung is calibrating the thing to fit there needs.There are apps that allows to adjust the saturation and if Samsung just upped it 10% from the get go you wouldn't have all the over saturated hate from people.