I think his point was/is that with new machines that don’t come with XP preinstalled (thus resolving the driver issues), “downgrading” to XP from Vista will have significant challenges because M$ is/will no longer be developing drivers for new hardware, whereas Linux will.
Well, considering Microsoft does not develop those drivers, I don't think you can expect to see them in the future.
Microsoft publishes guidelines for device driver development and can help you certify your drivers once created. But drivers are the responsibility of the device manufacturer to provide. Just like that Dell CD with all the drivers that took care of the issues the author complained about.
MS provides the OS; the device manufacturers provide the drivers. I don't really see the problem. Most Linux guys decry "OS Bloat" because of extra things in the OS install. Does that include drivers? Apparently not...
MS doesn’t develop drivers for new hardware, the hardware makers develop the drivers. MS ships a bunch with the OS, but with rare exceptions they don’t actually make them.