People communicate with each other -- and with their pets, and even with pre-verbal babies -- with gestures and not with keyboards.
I'm not sure that this is true now [1] much less that it will be in the future. While I'm not closeted in my mom's basement, I'd estimate that at least 50% of my interactions with my colleagues, collaborators, friends (incl. those of the girl variety), and family occur through keyboards. Think about it. Text, chat, email, social networks - even with the people I live with, we communicate extensively via keyboard. Even with a live-in girlfriend, we'd chat during the day as much as we did at night. Continuous constant availability hasn't taken away from in person communications, but they've made them much more extensive. Before email, sms, and mobile phones, I'd only talk to my SO in the evening - now it's short messages all day long.
That's my life, and I'm old. I look at the twenties that I work with, and they're even more virtual than me. Which is not to say that they don't interact with people in real life, but that they're continually interacting with them via a keyboard.
Yeah, the dogs don't have an iPhone. Yet.
until I can give my computer a dirty look or an obscene gesture to make it stop doing something I don't like, we'll continue to have a need for better human-computer interfaces.
Yeah, and how's that dirty-look/obscene-gesture interface working on the humans, or pets, in your life? If someone gets that working for computers, that'll be the only place it works.
[1] for everyone - realizing that this is a first-world problem, but we are talking about human-computer interfaces, so let's limit the discussion to the small subset of humans on the planet who use computers),