Steve Jobs wasn't pronouncing the death of the Mac when he unveiled iPhone 4 at Apple's (Nasdaq: AAPL) annual Worldwide Developer Conference last Monday, but he may as well have been.

To review, the new iPhone provides features we've long expected (multitasking and an integrated email inbox), and others that would've been a surprise if not for a drunken employee and the sleuths at Gizmodo (video calling and HD video recording).

But the real story lies underneath these features, where the new iOS4 operating system and existing A4 chipset hint at another architectural shift for Apple, one akin to the move from PowerPC to Intel's (Nasdaq: INTC) x86 architecture in 2005. Only this time, the Mac isn't leading the way forward.

The iPhone and iPad are.

No more Intel inside?
To be clear, Intel isn't losing anything right now and may not for some time. Neither the iPhone nor the iPad were ever Intel gadgets. Apple used Infineon chips for earlier generations of its iPhones, and the iPad is the first device to use the A4 chipset designed by former IBM chip guru Mark Papermaster and the team Apple acquired with P.A. Semi.

What's interesting here is the convergence. The iPhone and iPad share a common architecture (iOS4 and A4). I think the Mac is next. After all, what reason could Apple have for not moving all of its hardware portfolio to a common platform after having done it so many times before?

Look at how Apple approaches software. Vertical integration is the norm, even to the point of controlling the interfaces to which iPhone programmers are allowed to write. The advantage of such controlled environments is control, for both the manufacturer and the user. Expecting anything less from Apple in hardware design -- even at the chip level -- would be folly.

What's more, the argument for keeping Intel paired with Mac OS X -- compatibility with Microsoft's (Nasdaq: MSFT) Windows -- is becoming more irrelevant by the day. A slew of emerging standards either created or endorsed by Apple have made the Web the OS layer for thousands of new software applications -- WebKit, JavaScript, and HTML5, to name three.

They're widely responsible for enabling cloud computing, and the building blocks for Palm's highly regarded webOS smartphone operating system and Google's (Nasdaq: GOOG) Apps suite of online productivity software.

So what you're saying is?
I'm saying that iOS and Mac OS X are going to merge at some point, creating a new operating system built to run on the A4 (and 5, and 6, and 7, and so on) architecture. It'll be designed for highly interactive, open Web standards. Developers will adopt it because it'll already have played host to hundreds of thousands of software apps.

Sound scary? It should. This is nightmare scenario for Hewlett-Packard (NYSE: HPQ) and everyone else in the device and PC business, but for Google and Microsoft most of all. Why? A tightly integrated Apple ecosystem would give users the ability to pull from apps to perform any task, on any iDevice, and in any location.

No other supplier would be able to match that degree of pervasiveness:

  • HP and Dell have the hardware but not the software.
  • Microsoft and Google have the software but lack the hardware.
  • Research In Motion (Nasdaq: RIMM) has some of the hardware but nowhere near the software.

Only Nokia (NYSE: NOK) has a comparable vision, with smartphones and netbooks powered by its popular Symbian operating system, which already enjoys a global customer base. The Finnish phenom's worldwide reach would challenge Apple's ambitions.

Everyone else has a lot to fear. Jobs introduced iPhone 4 Monday, and in the process set in motion what may become the most important architectural shift in recent computing history.

How soon will Apple release an A4 Mac? Discuss in the comments box below.

Apple is a Motley Fool Stock Advisor selection. Google is a Motley Fool Rule Breakers recommendation. Intel, Microsoft, and Nokia are Motley Fool Inside Value picks. Motley Fool Options has recommended covered calls for Intel and a diagonal call position on Microsoft. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Tim Beyers is a member of the Rule Breakers stock-picking team. He had stock and options positions in Apple and stock positions in Google and IBM at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. The Motley Fool has a covered strangle position on Intel and is also on Twitter as @TheMotleyFool. The Fool's disclosure policy was last seen raiding the company refrigerator.