Even though 64-bit processors and operating systems have been out for quite a while, and most of the initial driver compatibility issues have already been sorted out, many are still on the fence whether to make the switch. Microsoft has previously mentioned they expect a majority of Windows 7 installations to be 64-bit, while Apple has been pushing hard towards a transition with its latest "Snow Leopard" Mac OS X release.
When it comes to software, however, 32-bit is still hanging on strongly. Thus you may find it a bit surprising to hear Microsoft is already planning to incorporate 128-bit compatibility with its future Windows 8 and Windows 9 kernels. The news came into the limelight after Robert Morgan, a Microsoft Research employee, posted some intriguing details on his LinkedIn profile. There he also claims to be forming relationships with major industry players, including Intel, AMD, HP, and IBM, to work on the project.
Many are expecting Windows 7 to be the last 32 and 64-bit operating system from Microsoft. While this certainly doesn't mean Windows 8 will come in 64-bit and 128-bit flavors -- and to be honest it sounds unlikely being just three or four years down the road -- at the very least it appears Microsoft is being proactive and getting ready for the eventual shift, whenever that might be.