I could see the multi-touch screen but the rest is mostly unimportant and adding extra cost where it would not return high value.
How is not having clickable thumbsticks important. I can't even think of a PS3/360 game that don't use them and all the buttons. Lets take CoD for a moment, the analog sticks are used to run on the left stcik and knife or crouch on the right. Would they now need to start adding standard buttons/actions to the touch screen. You can say this won't be a big problem, but it will just slowdown games and response times. Not only that but needing to use a massive screen just to get the buttons you need seems like a waste of bateries.
And with the WiiU, are they getting rid of rumble now?
CoD plays really well on Wii and it uses a completely different control screen without clickable sticks. Its just not important and will work just find without it. However, I do see that it would be a added value as it does give two extra button options.
My only problem with clickable sticks is that I often accidentally click them. While playing Gran Turismo, my windshield wipers are always turning on and off. I guess I tend to jam the sticks around rather hard, but having important things mapped to the clicks has always annoyed me. I realize I'm in the minority in this regard, though.