There have been many comments on the Windows Seven news thread, due for release in 2010 and the decision to ship it in both 32/64 bit flavors. I read an interesting article on Computer World this morning that reminded me of the 16 to 32 bit transition, it took 10 years...
The consequence of that is that PC users had ample time to switch to the new architecture, I mean who in 2005 was still using a 486 computer? (unless it's a Linux proxy server)
"The last time around, Microsoft was gentle in moving users from 16-bit to 32-bit, taking a decade to complete the transition.
Starting with 1990's Windows 3.0 and finishing with 2000's Windows ME, Microsoft released five versions of Windows supporting both 16-bit and 32-bit. In comparison, Windows 7 will be only the third Windows version, after 64-bit XP's arrival in 2005, to sport dual 32/64-bit compatibility.
Apple Inc. has a similar hybrid strategy. Its upcoming Mac OS X 10.5, a.k.a. "Leopard," is a true 64-bit environment that will ostensibly also offer full compatibility with 32-bit applications on, for instance, older PowerPC-based Mac hardware.
Companies, especially those running esoteric or in-house-written applications, will be the happiest to hear that Windows 7 will still support 32-bit software, since it will allow them to avoid expensive rewrites if they decide to upgrade.
The number of bits determines how large the chunks of data a component of the PC can process, which determines how much data it can handle and ultimately how fast it can perform. For instance, '80s-era PCs with hybrid 8/16-bit architectures were limited to a maximum of 64KB of RAM.News source: Computer World
In contrast, a modern PC running a 32-bit version of Windows XP can utilize up to 4GB of RAM. Meanwhile, 64-bit versions of Windows XP and Vista can support up to 128GB of physical RAM and 16TB of almost-as-fast virtual memory."