The iPad 2 launch seems to have gone well, Apple's lack of pre-orders resulted in the fun publicity stunt lines they love (as opposed to the Verizon iPhone 4, which was up for pre-order, because Verizon doesn't understand "free advertising", and everyone stayed home and bought that).
The reviews aren't just glowing, they're basically blowjobs for Apple:
Joshua Topolsky at Engadget "It might frustrate the competition to hear this, but it needs to be said: the iPad 2 isn't just the best tablet on the market, it feels like the only tablet on the market."
David Pogue at New York Times "But you know what? The iPad will still dominate the market, because it dominates in all the most important criteria: thinness, weight, integration, beauty — and apps."
Walt Mossberg at WSJ … Wait, that's not a blowjob. Gruber debunks Mossberg's fairly unbalanced caveats.
Looks like iPad 2 is a very nice upgrade of the iPad 1. I'm still happy with mine, so I'll probably wait for next year's model; if you don't have an iPad, you should get it.
So, when do we turn the lights out on desktop/laptop computers? I use my iPad as a reading/web surfing/Twitter sidebar (and it is my constant companion because of that), but I can use it for a lot more. What I MUST have a laptop for:
Long writing in BBEdit (MAN, if there was BBEdit on iPad… I could happily use the BT keyboard instead of this). I could work in Pages, but I don't like WYSIWYG editing, need BB's regular expression support, and would have to write some AppleScript to pull Pages docs out of Mail and convert them to HTML; my MultiMarkdown process is easier. So one app away from usable.
Software development. No Xcode or Python on iOS. Yet. YET. And it's probable that this will be the last thing to leave the desktop, not so much for technical limitations as for Apple's control issues, and to get iOS devs to buy Macs. If you want to develop webapps on iOS, you already can.
Unix & AppleScript toolchains. Half the time I solve problems by gluing together a few other tools. None of the scripting tools I need are on iOS, and it doesn't have AppleScript, though it's the same basic OS, and wouldn't be hard to expose as services. I doubt that Apple will bother with classic AppleScript, but some kind of scripting is inevitable. You can, if you know the app, sorta do this now, with hyperlinks: Some apps respond to queries. If they let you specify a "callback URL", you could make something like Automator by calling one URL, then using the results to call another, etc.
Highly (sorta) demanding videogames like Minecraft, Myst Online, and World of Warcraft. But the iPad has Minecraft coming soon, classic Myst and Riven, and Pocket Legends MMO. iPad, iPhone, consoles, and handhelds are a better gaming experience than a desktop PC in almost every way, and cost 10-20% as much.
Other people have different lists, of course. Audio and video people need Final Cut Pro, not iMovie/iPad… 3D software like Blender or Poser are massive CPU hogs, in addition to burning video cards. But it's getting there. You can do amazing things in GarageBand/iPad, that are simply not possible with a desktop.
Tablet performance hasn't caught up to desktop yet, but soon will: iPad 2 is roughly 4x slower and less memory than a MacBook (which is adequate for all but the VERY highest end work). With Moore's Law, that's 3 years, 2014, and in 2017 it'll beat a current Mac Pro. While desktops will get faster, they're already a couple years past the point where 99% of the market makes use of it. And it may go faster, since ARM processors are simpler to develop & upgrade than Intel; Intel's made good use of scale, but ARM has even bigger scale now.
For user interaction, the iPad is already better. The mouse is a 50-year-old set of Etch-A-Sketch(tm) knobs moving a single dot around a screen, two levels of indirection; touch gives you direct manipulation. If an app needs precision, it can touch-and-hold to show a loupe (like the clipboard controls in text areas), or let you zoom in (like Brushes does). Your finger is the best pointing device there is, and you have 10 of them (usually). You cannot tap two or more places at once on a desktop, and the desktop thing of trying to hit a 1 or 2 pixel target never made any sense.
Desktop windows and dialogs and "spaces" are a pain in the ass. I just had to move 2 windows and a dialog box aside to get to iTunes to sync my iPod nanowatch. I do that crap a hundred times a day. How much of my life has a windowing GUI wasted? I'd like better background tasks than iOS handles, more like WebOS's cards, but complex GUIs were the wrong direction to go.
For display, an iPad can drive a monitor or projector. Hook it up to your Apple Cinema Display, and the app will either be mirrored on the big screen (useful for demos) or show whatever external video it wants, leaving the iPad as a controller.
If you need a physical keyboard for writing, the bluetooth or dock keyboard are exactly the same as a desktop's.
So I'm thinking somewhere between 2014 and 2020 at the latest, the desktop just goes away. There'll be servers and a few high-end workstations running dedicated software, and everyone else will be using tablets. And by "tablets", I mean iPads, because at this point I doubt anyone else is competent to produce a competing tablet.