Actually, I doubt the additional row of icons makes a huge difference (though, maybe it does help videos), but I bet the additional space inside the phone is useful.
I just want to be able to read more text at a time... seems like every time I open an email or webpage, at any comfortable size I get less text than I can read in a few blinks. I won't know until it's in my hand, but the extra height and fullscreen Safari sound pretty great to me (also, more room for my hands to make those damn pinching motions– the tall and large communities will appreciate it).