Wow, are we really afraid of touch screens now? That's just silly. I'm not suggesting that Apple will do this, but if the next rMBP came with a touch screen it would have exactly zero impact on any of us. It's not going to impact your usage of the machine in any way if you don't actually use it. I can't imagine the power draw is relevant, and otherwise it's a feature that you can ignore or use as you wish.
Now I understand where the fear comes from... as actual computer users we're afraid of the tabletification of real computers. That's a software concern, and I suppose you could argue that when touch screen hardware exists the software will begin to change to accommodate it.
Maybe that's true to some degree, but I also kind of doubt Apple wants to follow in the footsteps of MS with the terrible reaction to Windows 8's amazingly bad new start menu (ironically the core of Win 8 is an improvement over Win 7 in terms of stability and performance). In other words, Apple isn't dumb enough to make use of a touch screen mandatory (or even a primary input method to begin with) even if they do implement them.
There will be a touch screen Macbook. Not today, probably not tomorrow, but it's coming and it's going to be completely ignorable if you don't find it useful.