I think tablets are here to stay for now.
Wearable computing as it exists now is a gimmick. Glasses can display maps and text, fine, but how about movies, photos, games? Those media need opaque backgrounds, not transparency. And if the glasses can switch to opaque, they automatically become a safety problem outside the home. Imagine driving your car wearing Google Glass, when it accidentally starts playing Avatar 3D in both lenses.
Phones with bigger screens are fine, whatever. But if you want a larger than pocket sized screen, you will need a separate device.
Flexible displays seem cool on paper. But I think it's a case of "it's cool because we can do it". Ok, my tablet can bend. Now what? How do I flatten it out when I want to read or play a game? How do I keep it from bending when I don't want it to? A truly useful flexible tablet will have to be a lot more advanced than just having a bendable LCD. It will require a revolution in metallurgy and/or plastics that can facilitate multiple physical states besides just flexible.
In the near future, I think we'll see the current form factors refined. Lighter stronger metals and plastics. Wireless conductive charging with battery life that is measured in days, not hours. Advances in LCD manufacturing that produce homogenized flawless results. Screens that can be switched from backlit to e-ink at will.
Gestures will surpass physical touch. Scrolling will be done with the eyes, the wave of a finger, or a nod, as a seamless feature, not an accessibility toggle.
Maybe some day you will be able to interact with a scalable floating proxy of a screen, with the CPU existing as a small wireless transmitter that stays in your pocket. This issue of transparency comes up here too though. Not sure we'll ever get past that. Even Princess Leia was see through.