No DirectX10 for WinXP?

As reported today by Gamasutra, sources reference a recent event in London, and statements by ATI Technologies chief Richard Huddy, as strong indictors that Microsoft will not be releasing DirectX 10 APIs for Windows XP. The article from Gamasutra:  

According to sources quoted by website XbitLabs, Microsoft will not release version 10 of the DirectX application programming interface (API) for Windows XP, but will instead make it an exclusive for the forthcoming Windows Vista operating system.The news, which has not been officially confirmed, was apparently mentioned at a recent event in London, with ATI Technologies’ software developers relations chief Richard Huddy commenting that Windows Vista will integrate DirectX 10 and DirectX 9 APIs for different types of hardware, but that Windows XP will not get DirectX 10 support. The lack of DirectX 10 support will essentially place a glass ceiling on software technology created for Windows XP, with new graphics cards specifically designed for DirectX 10 (planned by both ATI and nVidia for later in the year) only being fully utilized when using Windows Vista. The logic behind Microsoft’s decision is obvious, in that it further enforces the idea of Windows Vista as a necessary upgrade for game players, and allows Windows Vista and DirectX 10 to combine much more efficiently, but it also has the risk of further narrowing the market for cutting-edge PC games. Currently, Windows Vista is not expected to be widely available as a stand-alone release until January 2007

If this information is official, I think Microsoft will eventually change their mind anyway, for a few reasons:

1. Most people buy a new computer rather than upgrade their existing one. Sure gamers like us may get in their, wipe the drive, do a clean install, and all that. But for the most part, that's not really been proven to be typical consumer behavior.
2. It's just not that easy. I haven't seen a new OS yet that wouldn't truly benefit from a completely wiped drive and clean install. How many people are comfortable with that?
3. Games are so mainstream now, the "average person" can be considered a target for anything that benefits a gamer. This is sort of trickle-down theory applied to gaming. Some cutting edge physics system in a next gen graphics engine can make Lemmings more fun.
4. WinXP has been on the market for years, but the growth and dominance didn't happen overnight. Even Microsoft discontinuing support for Win95 haven't stopped people from not upgrading to XP, much less 98.

Smartly, Microsoft's system requirements for Vista are not that steep. Even a fairly robust computer bought four years ago should have more than enough power to take advantage of the highlights of the new OS. However, I doubt this will drive a new consumer comfort level with upgrading their OS. Basically, if this moves forward as is, forcing Vista on those who want DX10 will delay use of the API in all its glory for some time. Maybe into 2008 or 2009 even. Trying to get developers to use all the new foozles is going to be a bit tricky in the short term.