I think I'm still at the same place I was a few years back when the iPad first came out. Basically tablets (I am partial to Android and so probably Samsung's entry) are excellent for sofa/commute browsing (reading and simple gaming too), they are very good for some task computing: recipes, portable showrooms--very good when a designer is at your house and wants to show you images--and they are fine for simple messaging/communications, particularly as voice to text has gotten better. They suck for long form writing--whether blog posts or business email, or any other longer writing--and are crap for any gaming that wants to be immersive.
That means that they are probably good for about 90% of what people use computers for at home, and maybe 20% of work use. Not being able to do that last 10% at home, however, means that real, full on computers are still (to the extent that they are at all) necessary. Massive storage on the cheap, CD/DVD/BluRay players and writers, better graphics and keyboard mouse inputs are all still important.
Now, that said, things are changing rapidly and I don't think it will be very long before tablets are the home computers. HDMI connectivity to a television, USB or wireless connection to a network attached storage, and a bluetooth keyboard and mouse cover most of the difference between how people use computers and what you can do on a tablet. Pretty much the only things that are still missing are the raw power you can get in a desktop (or even a laptop), but most people don't need it.
Throw in a PS3 and you've covered most gamers, and there are only a handful of processor intensive tasks remaining for the computer (graphics, CAD, serious audio/video editing).
Still, those add on options that convert a tablet to a near-computer aren't exactly cheap, and it is still much cheaper to buy a low end desktop or netbook to get that functionality. That will change, however, and I think it isn't too far off that all computers will be tablets, with enhanced functionality via home network plus some accessories.
The form factor is still a question, and using a phone size makes much more sense to me than even a 7" tablet...but that is contingent on combining it with something like Google Glass for certain functions (reading) so that is further off than the tablet+ as computer.