apple seems to have settled into a rhythm of screen/body updates in alternating years to more substantial processor/internal upgrades. this is the internals year.
technically the screen is getting upgraded with pressure sensitivity this round, so there's at least that.
oh and not to be a negative nancy, but when i got the 4S, the screen actually seemed like a bit of a regression from the iPhone 4 screen. it had a slightly sickly green tinge that i saw on pretty much every unit i encountered. both the 4 and the 5 series and beyond have all had much more natural looking colours.
on the up side, the 4S was still my favourite iPhone!