The official statement reads as follows:
"Beginning January 1, 2012, Autodesk will have formally ceased support of the Microsoft Windows Vista Operating System for all new (and upgraded versions) of its products and services released in 2012.
Currently shipping versions and previous versions of our software (delivered prior to January 1, 2012) will continue to be supported on this operating system."
To read the entire FAQ document, click HERE: the move is based on Microsoft's termination of sales of the Vista Operating System and eventual end of support in 2012.
In a way, this is understandable: Vista was more of a transitional Operating System for Windows XP. It fixes many XP issues, especially in the 64bit version, but was never compelling enough for many firms to migrate to it. And with Microsoft's questionable marketing for Vista, or lack of, Vista never established itself in the corporate world.
So what's the problem you say: this is old news. And you are right: the problem is what is missing from the Autodesk FAQ that in my opinion is a huge disservice to it's customers. Autodesk will still list Windows XP as a viable Operating system for the current and at least the next version of AutoCAD/LT.
Most Windows XP users are most likely only using the 32bit version of the Operating System (OS): most AutoCAD/LT2012 upgrades from users still using this old OS had legitimate expectations that the new software would perform well, but they soon discover that "slow" has a whole new meaning, and if they regularly access DWG files of any significant size ( a low 12-15MB limit usually), the operating system simply gives up and crashes AutoCAD/LT.
This disease of making software appear truly usable with older OS is prevalent in the CAD Industry, Autodesk is not alone in this attempt to appear accessible to everyone (LT starts at $1200, AutoCAD starts at $4000, hardly accessible pricing), it's an almost universal disgrace with all software companies. If your software truly cannot do more that merely "function" in an operating system, it should not be sold to that market. This is espcially sad in the 32bit versions of Windows XP (Vista, and Windows7 are equally underpowered in the 32bit versions).
Look at Autodesk's current behavior to see the conflict: they currently offer Technology Makeovers to move companies to new systems (they do not install Windows XP or Windows 7 32bit).
Then there is the huge topic of using Workstations instead of Desktop PCs for CAD, including this Lynn Allen recent video inteview, and this well written review by a frequent AutoCAD contributor from CADSPEED.
Autodesk needs to take the lead in the CAD Industry and speak the truth: Windows 7 64bit (and the Apple offering of equal Horsepower) should be the only specified Operating System for AutoCAD/LT 2012 and higher. It should start doing so today, not when Microsoft ends support.