It may be worse than you think
This link is a long but interesting read:
http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.html
Buried deep in the bumf for Microsoft's new Vista release is a line that says it handles sound very differently. This kind of jolly PR spin is enough to chill the blood of those who rely on Windows running their audio production software reliably. Whenever a new version of Windows hits the street it tends to roil up the murky …
I can tell you firsthand that at the (large, international) media company I work for, the changes to the Vista media handling system ARE a big deal and a subject of intense discussion.
Now this does not mean we're panicking - while Peter Gutman's analysis /is/ chilling, Vista simply hasn't been through enough scrutiny to warrant a great deal of fear, only studious concern. But rest assured we are watching with interest and making alternate plans just in case.
What I will say is that when we talk, Microsoft (unlike Apple, whose products we also use extensively) generally really listens and makes changes to satisfy our requirements. Therefore we're fairly confident that even though it will be a bumpy ride for a while (which we will do our best to avoid), MS will eventually see the light and give us what we need to continue to work with high-quality media.