I've been thinking more lately about touch screen Macs. There's lots of talk in the community about how Microsoft has added touch screen to Windows and it's now time for Apple to follow suit. Just a few days ago, I was sent a link for the Air Bar, which is a bolt-on sort of thingy that sort of adds a touch screen to a 13 inch MacBook Air.
I have no inside knowledge but I think you're dreaming if you expect Apple to add a touch screen monitor to the Mac. Microsoft added touch to Windows because they were unable to successfully launch a separate touch interface. Even with that, Windows touch implementation still has a very long way to go before it is as intuitive or easy to use as iOS. Making a single interface that can satisfy both touch and keyboard/mouse users is no easy task and I'm not convinced Microsoft (or even Apple) can pull it off.
Apple will expand upon touch computing through iOS, not the Mac. The hold up right now is that iOS needs more power but that will come along with bigger and better iPads. You won't get your touch screen Mac. Instead, you'll get a gigantic iPad (or whatever Apple ends up calling it). For the Mac, the Touch Bar is probably all we'll ever get in terms of touch. If they do go further with touch on the Mac, however, I'd expect it to be a full touch screen keyboard, not a touch screen monitor.