You're right, its not that clear. From what I can make out, this new driver is designed to allow HD Audio Equipment makers to produce drivers easier with known good quality. It provides a HD Audio Driver without the manufacturers having to write their own. They say using these drivers, your sound will be glitch free. I imagine then that New Drivers from the manufacturers will need to be written for current HD Audio equipment to use these new MS drivers. If you have an Audigy 1, it remains to be seen if its possible to use these drivers on it, should Creative release a set for the Audigy 2. Creative might(!?) be able to provide a proper driver for the Audigy 1. But then again, there may be no support for current hardware. I'm watching this space. I havent been able to find if this will make any difference to other Audio cards not classed as HD. You can be sure there will be more information soon. above = best guesses having read 2 MS articles :)

Quoted from the article: "An audio device that is UAA compliant can rely completely on the operating system for driver support. Therefore, the hardware vendor does not have to supply a custom driver for the device." From what they've said, if you need it now, contact MS. Then they talk about the next OS (Longhorn) having it. I suppose you only need it if you have HD equipment and either quality or stability issues.