I'm thinking about converged devices, in a way. And about (paradoxically enough) about single-purpose devices. We're seeing, over and over, that nothing in isolation is really Ultimate Gadget-worthy. Your mobile phone, with camera, streaming video, Internet access, and GPS? Is a lovely converged gadget but would quickly become a picture-taking brick without some serious horsepower in the form of fixed-purpose devices backing it.
GPS is useless without satellites. Wi-Fi triangulation is useless without wireless access points, and access to servers that have geospatial information available. All the video streaming in the world is useless unless you have servers somewhere and infrastructure servers routers and networks to stream it along. The phone itself becomes a glorified walkie-talkie without the cellphone towers, data routers, and miles of fibre and copper in the ground. Oh? You can still take pictures? That's great, but somewhere there will have to be a photo frame, a PC, or a printer to actually do something with those photos unless you're happy showing off your 512 favourite photos (or whatever capacity the phone has) on a 2" screen.
Almost two decades ago now, I was introduced to the idea that technology wouldn't be useful until it was so universal and ubiquitous as to be invisible like pencil and paper was. In other words, you picked up a pencil and a piece of paper without thinking, without worrying about how to use it, where it came from, or how it worked. it was just - there. Like picking up a rock to throw at something. It's there, never mind geological forces and aeons of shaping.
And we're at this point now. Gen X and Y don't consciously worry about assigning an IP address, subnet mask, and broadcast address to their netbook, they just turn it on and use it. Boomers and some Gen X'ers with a penchant for how things work might poke around under the hood a bit and manually set packet and window sizes, but generally this stuff just works.
You don't worry about where to save your pictures, many apps already just send them to your Flickr or Picasa account, and your mobile phone photos can be sent to your bit.ly or blip just like any other message. Your GPS seamlessly downloads relevant maps and points of interest as you move around, and when you switch to movie mode and sit down in front of your favourite restaurant and give a vox pop review of the place, you don't have to worry where it's streaming to, it just happens.
About ten years ago I realised that there'd never be one Ultimate Gadget. There'd be unobtrusive single purpose devices that you'd never see, gadgets that you carried with you or used without thinking about much, and which would do the hard work of interconnecting and interoperating for you.
So I'm thinking that your next gadgets will be things you don't think about, that you pick up and use in the same way you pick up your keys to drive or open the door, and that, like keys and paper, perform specific actions - maybe more than one specific action, maybe a whole gamut. But you wouldn't be thinking about that specific function or how to make the gadget perform that action.
Oh and very small and very ubiquitous. We're at the stage where circuits are being embedded in plastics and paper. We're at the stage where the gadget becomes foldable, bendable, rollable, where research is ongoing to make devices that can change their shape depending on the function they're performing, and the flipside of that, where the gadget changes function depending on how you fold bend roll or twist it, which way you orient it in space, how fast you move it.
Back when I was forming these opinions, the average PC was an AT class 286 PC and it too all its brainpower to recognise a handful of words after days of training to recognise a single voice. Nowadays, it's common to speak to an AVR program over a telephone and speak menu choices in a wide range of accents and be recognised, even with background noise and telephony-quality audio.
Back then, I predicted that enough computing power and memory could be put into a device the size of a packet of cigarettes and recognise it's one user's voice with 99% accuracy, when in fact it's turned out that those electronics can be packed into something the size of an inline earphone dongle for an iPod Shuffle and recognise any user's voice with that much accuracy...
So I'm predicting that when the next revolution in converged, multipurpose, highly miniaturised and highly powerful gadgets comes along - you won't even realise it...