The author misses the point.
The whole point is to implement an interfaces that requires a Drect-X
3D card, making it much more difficult to put Linux, which uses OpenGL
3D, into a Vista PC.
The irony of course, is that most of the graphics card makers have
figured out that the market for "Direct-X Only" cards is very limited.
The have some great high-end cards that are optimized for DirectX, but
OpenGL can perform similar functions using standard cards and X11
There are now some very workable OpenGL to DirectX toolkits, which have
been implemented in some proprietary X11+3D Servers, but Microsoft is
trying really hard to make sure that machines that run Vista will not
be able to run Linux.
That strategy may backfire, since, by the time Vista finally does come
out in a stable, reliable, secure version, mosts PCs will have to be
"Linux Ready" to survive in the Marketplace.