Possibly. I don't believe that yet because too many people want a larger screen than your phone will/can provide. Not to mention the keyboard functionality. I'll keep my laptop, and relegate my phone to actually being a phone.
As far as tablets, we'll have to wait and see. They're still a niche product. I can see them replacing the laptop, if done properly.
Tablets are the future. Most people just need to consume data and that’s a great device for consuming info. The designers may still need a full blown desktop environment to design tools and widgets for the tablets.
And once that shift is underway, next who knows. More kinect like interactivity with holograhic projections or something like minority report.
You said "yet"... I would say "ever". Bookkeeping, spreadsheets, project management, graphics/video editing, programming, serious authorship - All of these require more real estate than a device can offer, or will ever offer, at least in the current form factors. For all the hype, most folks are still using handhelds as a glorified PIM (and that's really all it is). Folks seem to forget that computers do more than browsing the internet, e-mail, and appointments...
As far as tablets, we'll have to wait and see. They're still a niche product.
True. but without a real KB, same as any other handheld - 'Tablet' used to be a laptop with a turn-around, touch capable monitor - and even those have been unsuccessful, even with the capability of transforming into a laptop. So why would a tablet without that capability do better?
I think the device with legs is the netbook. Too small to be comfortable on, to be sure, but capable of doing anything a laptop can do. My tablet is awkward to handle, and too big to store easily on my person. I much prefer the netbook as a portable device - the clam shell design not only protects it, but makes it smaller for storage, and easier to handle in operation (just hook a thumb in the corner for a good grasp). And it has a KEYBOARD.