Give up the PC- Get real! You’d have to pry the keyboard and mouse from my cold, dead hands
Unfortunately, most people just surf the Internet, do some e-mail, and use a few specific tablet / phone apps... which will make the PC niche for consumers. That level of usage is great for tablets and phones though... and very convenient for travelling.
As for gaming... A keyboard and mouse is a must for me, which is why I don't own a console. I'm not saying that I'm not open to a "Minority-Report-Like" interface... but things like the Kinect are far from it. If the technology ever gets good enough... I'd consider gaming that way... but I'll probably be in an old folks home by the time that happens... and I won't want to break my hip!