> For one you're assuming that current computing capacity is enough for most people. However current computing capacity is enough only for current applications of it. In a decade from now however people are going to get interested in virtual reality and artificial intelligence.
I'm fairly sure most AI will be done in the cloud. We're already going in that direction, with stuff like Google Now.
VR is an interesting question... I'm really excited about the HoloLens, and I'm really curious to see where things go from there. Honestly, I think AR might become a big deal once we start getting wearables that aren't super clunky.
Actually, introducing wearables to the mix also introduces the idea of a personal cloud of devices. The concept of a PAN has been talked about for a while, but we haven't really seen it amount to much, unless you count things like Bluetooth headsets. Cheap, stylish wearables with phone-quality processors, however, can change all that (I don't think we're at either cheap enough or stylish enough yet... but that's a big "yet").
Think beyond smartwatches or googles, too. Imagine wearing a smartshirt and smartpants and smartshoes. Imagine if every single thing you wore on your body had a CPU in it. I think we'd avoid the problem of how small transistors can get just by sticking sources of computing power everywhere. Of course, this paragraph is all pie-in-the-sky far-future stuff. Prices will need to come down to the same range as normal articles of clothing, which will take a long time. And we'll have to have a seamless way to charge your clothes that won't add any more mental overhead. Nobody wants to say "sorry, I have to stay home, I forgot to charge my pants last night".
> But problematic are also the batteries, for which Moore's law never applied.
I think at some point there's going to be a backlash against thinness, and we'll start seeing bigger devices with thicker batteries. Wouldn't surprise me if portable power sources take off too (I'm already seeing external battery packs being sold at department stores, of all places), especially if inductive charging becomes a bit less clunky. Women might be a good driver of this technology: for example, I can see a system where you just drop your phone into your purse, and it magnetically attaches to a wireless charging mat plugged into a battery pack.
> Another problem is that no matter how powerful a phone can be, it's still handicapped by its small screen real-estate. The form factor of a laptop is optimized for productivity work while remaining portable. A physical keyboard is more productive than typing things on a touch screen. A 13-inch screen is more comfortable than a 4.7 inch screen for doing any kind of productivity work. I can go to a coffee shop, pull out my 13-inch laptop and instantly be productive. And transporting around a dock, a keyboard and a monitor to plug-in your phone in case you need it would be more impractical and would defeat the purpose of that phone.
Of course, you're assuming nobody will make a laptop-shaped dock that you can insert a phone into like a cartridge. Think something like the Asus PadFone [0], but with a laptop instead of a tablet. The only real barrier to that right now is that every shell has to be matched with specific models of phone, because every phone has a different size and shape, but I wouldn't be surprised if we start seeing standardized form factors at some point in the near future.
Better yet, combine that with a setup like the Surface Book, and you'll have a phone that can dock into a tablet that can dock into a laptop.
[0] http://d5htu2v3nddyh.cloudfront.net/media/catalog/product/a/...