The PC market made this shift years ago, as the arcane model numbers on new PCs mean nothing to buyers; at best, they're part numbers for IT and retailers to use. If a PC is in the stores, it's current, and what matters is its ability to run Windows 7. Next year, what will matter is the ability to run Windows 8.
The mobile device market isn't quite there, but it's close. Samsung uses the Galaxy S II moniker to distinguish from the previous Galaxy S generation, but it hasn't done so for other Galaxy devices such as the Nexus or the Note. Motorola Mobility does use version numbers on its original Droid series, but nowhere else (so far) in its Android device families. HTC also eschews version numbers.
The only mobile device companies sticking to version numbers are Nokia and Research in Motion. Nokia's numbers are meant to indicate relative value; for example, the Lumia 900 is apparently better and thus costlier than the Lumia 800, which is apparently better and costlier than the Lumia 600. RIM used numbers for the same purposes, but its four-character codes are hard to tell from each other, as they use some digits to distinguish carrier-specfic models, and they've all but lost their meanings. That's why people talk not of the BlackBerry 9900 but the BlackBerry Bold. Even old-fashioned RIM has recognized that family names -- Bold, Curve, and Torch -- make more sense to buyers. Maybe Nokia will get a clue as well and stop confusing part numbers with names.
What all this comes down to is the rapid maturation of device hardware. Though hardware is important, software ultimately creates the most value, partly by enabling the hardware's value. We'll see version numbers on iOS, OS X, Android, and Windows for some time, but the devices that run them, not so much.
This article, "Why there won't be an iPhone 5," was originally published at InfoWorld.com. Read more of Galen Gruman's Mobile Edge blog and follow the latest developments in mobile technology at InfoWorld.com. Follow Galen's mobile musings on Twitter at MobileGalen. For the latest business technology news, follow InfoWorld.com on Twitter.