Every nerd with a keyboard has written about Apple's fabled tablet/slate computer thingo and well, this nerd is no different.
I reckon the tablet will be Apple pushing the dream of an appliance computer. The iPhone is so perfect in that it's a computer (600Mhz CPU, 128Mb of RAM, 32GB of storage, wireless networking) that requires no computer knowledge to operate optimally. It literally is an appliance.
I really doubt the tablet is for "us" (as in hardcore users, or geeks), it's for every single person that keeps stuffing up their computer, or is clueless as to what their computer does. It will finally be a tool, rather than a computer. It's old-hat to use the parents as the metaphor for user friendliness, but my parents can rock the iPhone like no tomorrow and picked it up within a couple of minutes. They still don't know how to double click or right click a mouse properly, despite years of training and use. That's the sort of market (i.e: probably 70% of the western population) this thing and Apple want to snag.
It will be a total sandbox OS, exactly like the iPhone. Apps have to be approved by Apple. If it breaks, you simply restore it (somehow, that doesn't involve owning a traditional computer) or take it to a Genius Bar and they swap it over. No diagnosing faults, or repairs. The iPhone works exactly the same way now and I love it. If I have a real hardware fault within warranty, it's simply a matter of taking it down to a genius bar, and it's swapped over on the spot.??
You can do virtually anything the regular computer user does on it (iWork, iLife, Safari, iTunes??iChat, iCal and Mail.app), without needing to ever use Finder. You don't need to know how to back up, it's all backed up to a Time Capsule, or MobileMe (or both). You won't see OS X exported wholesale to this thing, the way the user interacts directly with a screen is so different to how they interact with a mouse and keyboard.
There will be a plethora of developers making apps for it, because your apps will be a piece of cake to install, be certified virus and spyware free and have the persuasiveness of the App Store. No hunting around for software, it's all there, direct from Apple, in one easy to search place.
Mundane things like text input (how does one type up long forum posts like this on it?) and if/how it syncs to a computer, I don't know how to solve, but I get the feeling Apple aren't just going to make a $1000 device that the prime selling point is that you watch movies and read books on. Sure, Apple would have lined up some wow-factor content to show off the capabilities, but that's just one of the things the device could do and how to lure in those who don't care about computing and care about real-life applications and the things they do now.
Basically, think of your iPhone. Now think of using that sort of experience (locked down OS, little to no multi-tasking, multi-touch interface), for general computing.
Even though it sounds a bit simplistic and not exactly the usual faster/better/stronger we're used to in computing, it could really be a revolution in computing for everyone, much like what the GUI was back in the 80s and early 90's (which has barely changed in 20 years). Even crusty old nerds like us, who have been surfing the interwebs when Netscape was #1 and a decade before YouTube existed would be won over because it will be so damn easy and exactly focused on the task or application, not on operating systems, optimisation, monitoring and the like. Nerds who like that have Linux and Windows to stuff around with anyways.
Bookmark this post and read it on the 28th of Jan and laugh at how stupid I am.