Is this the siren song for the x86 architecture and its great bastion, Intel?  It's hard to say for sure, but Microsoft's official announcement that it was supporting a more efficient rival architecture -- ARM -- certainly was met with little joy in Santa Clara.

At the show Microsoft CEO Steve Ballmer showed off a series of development systems running a "next generation version of Windows", which supported ARM.  Microsoft layered Windows 7's graphical user interface on top of new OS to show just how smoothly an ARM powered Windows system could run.

In total Microsoft showed off three different ARM development systems, with a system-on-a-chip design from Qualcomm (SnapDragon), Texas Instruments (OMAP), and NVIDIA (Tegra 2).  Mr. Ballmer did not officially announce when we might expect to see these Windows ARM systems, but it might be sooner than you think.

Microsoft has grown increasingly impatient with long-time partner Intel, who manufacturers somewhere between 80 to 90 percent of the world's computer CPUs.  Intel was being badly beaten in the fight for smartphone and tablet dominance -- or more aptly it never showed up, because it knew it was a fight that it couldn't win.

Microsoft had already long since gone with ARM processors in the ultra-power dependent smartphone industry.  But in the tablet sector it sat by and watched in pain as Apple and Google unloaded ARM based designs by the millions.  There were no Windows 7 tablets because Intel was unable to provide it hardware.

Unwilling to see its hopes anchored to what may be a sinking ship, Microsoft made the tough decision to jump onboard the ARM train, a serious vote of no-confidence for x86.  The message seemed clear -- Intel's promises of Atom-based Windows 7 tablets were welcome, but Microsoft sure wasn't waiting around for their release.

As ARM suppliers gains momentum they are hungrily eyeing the netbook, notebook, and PC markets.  Already we're seeing dual-core ARM CPUs show up in smartphones, and there's talk of eight-core ARM CPUs clocked as high as 2 GHz being delivered within a generation or two.  So is Intel's CPU (and to a lesser extent those of AMD) destined for a slow ride into the sunset, replaced by NVIDIA, Qualcomm, Texas Instruments, and Samsung chips? 

It's harder to say.  ARM's great hope is that it can parlay its sizable lead in power efficiency over x86 into market dominance.  ARM features a reduced-instruction set, versus Intel's cluttered instruction catalog.  And it has more integers registers, which eliminates the expensive process of renaming registers.  The net result of both of these architectural differences is that ARM can perform the same computation using less power.

And yet Intel could still pull out a victory.  As circuits have shrunk, leakage of current from the capacitors inside transistors has become a major issue.  In today's generation of ARM and x86 CPUs, leakage can account for as much as 40 percent of the power consumption of a chip.  As leakage becomes more important, process technologies may become more important, while subtle architectural advantages become more trivial.

Thus if Intel can hold on, it may stand a shot, thanks to its tireless advances in the field of process technology, which include "high-K dielectrics" -- special capacitor materials that combat leakage.  

On the other hand, developing processes is an expensive business, and if ARM begins a successful campaign into the personal computing market, it may starve Intel of the capital it needs to survive.

One thing is for sure -- for now consumers have compelling cause to buy ARM OS tablets, netbooks, and notebooks, a cause Microsoft has recognized and addressed.  Intel can only hope to weather the storm.