I know that we've had the eight-core Mac Pros and the the MacBook Air and, in fairness, the aluminium iMac (a machine I think is stunning, but I really don't like the keyboard), but they aren't, well, new.
Bear with me, as I think this needs some explanation - yes, we have had a myriad new products, but we haven't had anything to change the world in the same way that the original Macintosh did. Or, I suppose, the Macintosh II in the way it overturned the entire print and design industry and made Desktop Publishing mainstream. The iPhone is lovely, especially now it has 3G and GPS, but it's really nothing more than a logical extension of the Newton, although the Newton had handwriting recognition and the iPhone doesn't. I love my Blue Dalmation iMac G3, but the all-in-one form factor and simple, easy-to-use-yet-powerful design ethos are merely an update of the original Macintosh and all successive iMacs are iterative, rather than revolutionary. The Mac Pro is based on the Power Macintosh, which evolved from the Quadra series which grew from the ashes of the Macintosh II, whilst the consumer/low-end systems went from Macintosh to....well, Macintosh Classic, Colour Classic, LC, Performa (essentially reboxing the same technology), to the iMac. All compact, all usefully quick without setting your hair on fire and all pretty well designed and screwed together.
So where is the new paradigm shift? It's easy to watch the launch of the original Macintosh on youtube and think of it as hokey and rather sweet in a "aww, look at them going mad over something with less power than my phone" manner, but in 1984 the technology being unveiled was a world apart. In those days, even so-called "Personal" computers required expertise to use, as you loaded your games via a command line, or had to use a DOS Prompt to find your text documents and disparate interfaces and menus for your different packages. To put it in context, your PC keyboard used to have a clear plastic flap at the top under which you'd put your inlay (that shipped with each package you used) that told you what the 12 function keys did (at least three commands per key - the key, the key with Shift held and the key with ALT held). The Macintosh changed all that at a stroke. A child could use it, it worked logically and the interface was consistent across all packages. One of the least thought-about and most beneficial things that Microsoft hijacked when they pillaged Apple's IP during the creation of Windows was that idea of a consistent set of commands - CTRL+C for copy, CTRL+S for save, etc.
It is very hard for those people who grew up after the fallout of the introduction of Macintosh to understand just how far-reaching its impact was - they expect things like copy/paste and drag and drop. They expect their standard key commands to be consistent and they really fail to grasp the fact that all of it, every single thing they now see as "computing" is, in some way, linked back to that little beige box that spoke like Stephen Hawking and played a bleepy version of "Chariots of Fire" when an excitable guy with floppy hair and glasses pulled it out of a bag. Yes, I am sure that people will come out of the woodwork to point out that Xerox Parc had developed the bones of the WIMP (Windows, Icons, Menus, Pointer) interface and that, no doubt, some guy had created a full windowing, multitasking interfaces for UNIX in the 1970s that I don't know about, but the original Macintosh created the desktop computer revolution as we know it. The Newton created the first usable PDA (before we even know we needed one) and the Mac Portable was, despite the execution, the first attempt to make a portable computer that was a full equivalent to a desktop machine (remember, at the time you could buy an Collosus PC which had a 10" CRT monochrome screen and an 8086 CPU and a couple of floppy drives and that was about the size of a suitcase, so the Mac Portable wasn't that bad).
So, the question remains, what's the next paradigm shift? Personally, I don't think it's the "cloud", with everything on the web and computers just accessing information and applications when needed - the restriction of bandwidth precludes any idea of it being faster than a decent machine on your desk working with local files. Besides, we already have web-based applications and data storage, so it's nothing new. Touch and gesture control is just a way of integrating the trackpad or mouse to the screen, so it doesn't really bring anything new and whilst we are already seeing some convergence with data push/pull from handheld/phone to web to desktop and back, you could sync your Newton to your Macintosh many moons ago. I think that where we'll see the next revolution will be in convenience. Think about it - at the moment you might have a MacPro or iMac, a MacBook of some kind for working away from your desk and an iPhone/PDA phone for keeping in touch when you are travelling. This means you have at least three devices, but imagine if you had something like and iMac with a Wacom Cintiq (the display/tablet) that acted as your keyboard/input and document "dock". If you wanted to save a web page you drag it off the main screen and onto an area of the "tablet", which might have a keyboard attached (given how thin the new mac keyboard is, it could slide out). When you then go out of the office, you unplug the tablet and take it with you and it's a fully functioning mobile Mac - low power CPU (like a MacBook Air), maybe even built-in 3G, with an iPhone-esque interface for your stored web pages, documents, etc, but which has fully-functioning desktop applications and, say, 20gb of flash drive - enough to store a few tunes, your presentations and your documents for the meeting, all in a tough A4 sized slab that fits in your bag neatly, unlike a laptop - hell it could even have solar cells to top up the battery. If it's got 3G, you could bluetooth a headest to it and make calls, then get back to the office and dock it back to the main part of your Mac where it automatically updates your files with any changes made to the copies on the tablet and recharges the tablet battery.
From a users perspective, your work becomes seamless, you're not having to use USB sticks, or email yourself files to transfer from desktop to laptop and you don't even need a phone. It's nothing new, really, as it's a logical extension of the old Powerbook Duo/Duo Dock system, but I think it's something that would appeal to home users (surf the net from the sofa or stream movies to the tablet whilst the main machine burns tunes to CD or suchlike) and business users, for the reasons described previously, alike.
I know that it's technically not a new paradigm in computing in the same way that the original Macintosh was, but I think that something that is so flexible and useful would become indispensible to consumers, students and professionals and the fact you wouldn't need to physically transfer files from one machine to another takes a lot of the pain out of using a computer for practical tasks and makes it much more acceptable to those resistant to technology. I think it would be the first step towards making the Macintosh as ubiquitous as the TV remote or the microwave - which is no bad thing, as such a product would form a sound base for stronger Pro-grade machines, or even tie-ins with car manufacturers to create in-car Mac/GPS entertainment systems, for example.
After a fairly heavy weekend, this seemed like a sensible suggestion, but I'm willing to hear your point of view!