The Macintosh faithful are getting really antsy. There've been no new models (I'm not counting minor CPU speed bumps or additional RAM capacity) of the mainstay MacBook Pro since 2012, the iMac since 2013 (2015 if you count the Retina model -- I don't), the MacBook Air since 2012, the Mac Mini since 2011, and the Mac Pro since 2013.
Some Macs, especially the once-highest-end Mac Pro, have specs that make Mac enthusiasts embarrassed when they see the specs on the newest Windows PCs. Thus the rumor mill is working overtime again in hopes of an October surprise of revolutionary new Mac models
But maybe we don't really need new Macs. After all, the PC market is on a years-long slide, as people keep their PCs (and Macs) for extended lengths, spending their tech dollars on smartphones and tablets. And the usual reasons to need a new PC (or Mac) -- rather than simply want a new model -- don't really exist.
What drives PC upgrades are games, and gaming has never been big on the Mac. The need for the latest CPU, graphics processor, storage bus, RAM, or memory bus isn't there for Mac users -- no pressure there.
Graphics and video processing typically drove Mac performance upgrades, but there's not been much need for more oomph in that space. Thunderbolt is plenty fast enough for disk storage, and most high-end Mac models are perfectly suited for the demands of today. (The Mac Pro is now feeling inadequate for pro-level video editors and 3D modelers, but all it really needs is a speed bump in its CPU, graphics processor, and Thunderbolt bus, not a redo.)
"High-end" is the key here. Long-term Mac users know to buy the most expensive Mac they can afford, because it will keep its bang for years, costing less per year as a result. TCO thinking, baby!
With Apple moving away from user-upgradable components on most of its Macs in recent years, it's been more critical to get the most-maxed-out Mac you can. Power users have done so, and most can work with their existing Macs for years to come. A maxed-out Mac should compute comfortably for six years. (If you bought a low-end Mac, to get that "bargain" price, you're no doubt feeling the low ceiling after a couple years. Thus, max out your Mac.)
There's also very little technology change driving the need for new Macs. USB-C is the new "in" bus, but if you have Thunderbolt, you don't need USB-C. USB-C peripherals for pro users, like high-capacity drives and drive arrays, remain scant. Plus, they wouldn't be any faster or give you new capabilities, so why replace the Mac and the peripherals simply because tablets, smartphones, and a single Mac use USB-C? After all, that single Mac is the underwhelming MacBook 12, which in any case is designed to be a companion Mac rather than your main Mac, as if it were an iPad Pro running MacOS. It makes no sense.
The last five versions of MacOS run comfortably on nearly all Macs released since 2011, so that's no reason to get new hardware.
There are no new technologies that require new hardware on your Mac. Wi-Fi Direct, Bluetooth Low Energy, and USB 3 are now old news on Macs and, more important, their peripherals.
Anyhow, it's unlikely Apple will create such new technologies that require technology not already in place -- it hasn't done so for years, but instead has been trying to move to PC standards. Thunderbolt is the only significant new PC technology pioneered by Apple in recent years -- and that was five years ago. Besides, Thunderbolt is not a Mac technology, but a PC one that Apple adopted early and vigorously, while PC makers stuck with USB 3.
Apple's other fairly new bus technology is Lightning, used on iPhones, iPads, and iPod Touches. Earlier this year, this Apple-proprietary technology came to the Apple keyboard and mouse, as a charging cable. But it connects to USB on the Mac, and is slower than USB, so it's not a technology that makes any sense to make native to the Mac.
The interminably rumored OLED touchbar on a new Mac keyboard? Again, it's not actually a technology, and the idea of keys with labels that change based on their state is not a new idea -- or a particularly successful one. If Apple delivers such a keyboard, I don't see why it would need a new Mac to work or why you would replace your Mac to use it.
In some respects, Apple seems to have given up on Thunderbolt, with the discontinuation of its Thunderbolt Display, a marvelous display that was also a hub for Ethernet, FireWire, USB 2, and Thunderbolt devices. There is nothing else like it on the market, and Apple has (at least so far) not replicated its universality with a USB-C version, despite 2015's MacBook 12 use of USB-C. That suggests to me that USB-C isn't the Mac's future, though maybe one day it'll be the iPad Pro's.
But assume that USB-C is the Mac's future and new Macs are coming and will require people to abandon their Thunderbolt peripherals. Given the cost of such peripherals on top of that of a new Mac, that's a decision most users would defer as long as possible.
More likely is keeping Thunderbolt, bumped up to the current version 3, while replacing USB 3 with USB-C, which would also likely subsume the MagSafe power port as done in the MacBook 12 -- and lead to the need for similar ugly dongle adapters for the bazillion USB cables we all have. Still, that's a standards upgrade, not a meaningful new capability.
Also possible, given Apple's predilections, is that Apple has decided it's time to cut the cords and move everything possible to wireless connections. Thunderbolt would remain the multiprotocol external bus for high-capacity backup drives, monitors, video-editing gear, and so on (pro needs, basically).
Just like Ethernet is faster than Wi-Fi for dedicated, high-use backbone connections, Thunderbolt and USB-C are each faster than Wi-Fi, Bluetooth, and so on. You need at least a couple backbone connections, even if you move slower, lower-throughput peripherals to a wireless protocol.
That's been the approach of the iPad, MacBook 12, MacBook Air, and iPhone 7, which use Wi-Fi and Bluetooth for most peripherals but still go through Thunderbolt or (the ironically slower) Lightning for the heavy loads.
Perhaps there's a new radio technology in the works for wireless displays, or Apple will adopt one of the several wireless display standards like WiDi/Miracast and DLNA that have gone nowhere on the PC market that would take monitors out of that backbone equation -- or use its own AirPlay. But I doubt it'd be good enough, especially when you have several monitors and Macs in use. There's a limit to how much capacity radio waves have, as we know from our smartphones' cellular and Wi-Fi connections in crowded places.
Still, none of this is a reason to replace a perfectly good Mac.
My advice: If your Mac is long in the tooth, wait till mid-March before replacing it. Maybe we'll see new models worth the cost and peripherals upgrades by then, maybe we'll see the same models we have now with faster processors and more RAM, or maybe we'll see nothing (in which case, get the most-maxed-out Mac you can afford).
If your Mac is a few years old, find something else to satisfy your consumption impulses. Time for a new stereo or home-automation gewgaws?
And remember: PCs haven't changed in years, either. Other than the usual performance upgrades, a PC today is no different than a PC of 2012. The big change since then in the PC world has been the so-called 2-in-1/hybrid/PC tablet, epitomized by the Microsoft Surface Pro. Ironically, none of those devices is about new technology, but being more like an iPad while still being a laptop.
So, any PC envy is misplaced. A PC is still a PC.