Those would be a big deal if you only ever want to use your computer as a laptop. If on the other hand you sometimes wish to use it on the go, sometimes as a laptop, sometimes as a desktop, a smartphone that can connect to a larger screen suddenly becomes a vastly more interesting choice.
I'm just not seeing this, no matter how many times tablet evangelists repeat it. How is a tablet with a detachable keyboard that you have to lug around separately more convenient than a laptop which has it built-in?
"Power users" that "need" a physical keyboard are a tiny minority.
Since by "power users" you apparently mean "anyone who uses a computer for anything more than YouTube and AIM," I am going to have to vehemently disagree that they are a minority at all, let alone a tiny one.
As the same time, even for many of us that do need a physical keyboard some of the time, a tablet and/or a smartphone are viable second or tertiary computing devices replacing additional PC's and/or can be a primary device with "extras" such as the Atrix or the EEE transformer.
See, this is the difference between "can" and "should." Yes, it's possible to use a tablet with a Bluetooth keyboard in place of a laptop, but that doesn't make it a better option. Separate Bluetooth keyboards require a case like my brother has in order to not be a pain in the ass, and while snap-on keyboards like the Eee Transformer circumvent that, in either case you're just making it into a poor man's laptop.
Which raises the question,
why not just a laptop, then? They're cheaper, they're nearly as compact, they have a better software selection, and you don't have to tote around a separate freakin' keyboard if you feel you might need it (or leave it behind thinking you won't and then find that you do after all.)
frankly I can't imagine any situation where we won't eventually get to a product where the screen and keyboards are "dumb" and the computer stays in our pockets unless we want to use a phone sized screen
I can. I recently acquired a 12" PowerBook to play with, and from the moment I switched it on I realized just how tiny an 8-10" screen like my Eee or typical tablets have. My nearsightedness doesn't affect anything at such a close range, and even then I had trouble switching back to my Eee; I can only imagine how older or more visually-impaired users would feel when confronted with a small screen like that.
the appeal is to carry your desktop with you; walk up to a screen and it's all there instantly, with all your data and everything. Having state (data and/or running processes) in a stationary computer if one that fits in your pocket can hold it all just seems silly.
Laptops already provide that, and often with a decent-sized screen into the bargain. (
And they don't require a particular docking connector since any decent laptop will have VGA or mini-DVI out and USB or PS/2 ports for a separate keyboard and mouse, if you so desire.)
And while desktop PCs might not be as convenient generally as laptops or other portable computers, they offer full access to all the expandability the market offers, up to gigabytes of RAM, terabytes of hard disk space, and the best CPU and GPU horsepower out there, and that's something
no portable computer can claim. Yes, that's probably not necessary for most users, but the set of people who can make significant use of more than what a laptop or tablet can provide is most certainly non-negligible.
Incidentally, it's that dream that gave us VNC back in the day, though of course that was coupled with centralized computers, - Oracle and Olivetti's research lab used RFID badges couples with VNC to bring up peoples desktops whenever they walked up to a workstation 
You'll note, however, that the primary use of VNC in the personal-use computing world is to allow netbooks and tablets to access the storage capacity and computing power of desktop PCs.
Both were outsold massively last year by smartphones, and this year they are being outsold *combined* by smartphones.
...
I don't think we're anywhere near the boom phase for either tablets or phones yet.
By your own claims, tablets and smart-phones have gone from their entry into the mainstream with the release of the iPhone in 2007 and the iPad
last spring to the new Next Big Thing as far as the entire industry is concerned.
That's a boom. They're selling like hotcakes, everybody's making them, and as far as the press is concerned they are Officially Hip. The question is, what happens when they're ubiquitous enough that they stop being cool, and the public frenzy is diverted to some new trendy gadget? They'll be left with only the people who really want them and are comfortable using them, and who knows what percentage of the peak market share that will be?