MS will be blocking the loading of all drivers not signed by MS. Signing the code is expensive, particularly if you're an open source type trying to provide code for free. There's a hack to allow unsigned drivers, but the user has to approve it on every boot, so you have to hang around for your BIOS to finish, hit F8, and select the "approve unsigned drivers" option.
So those of us who depend on free 3rd party drivers like the free openvpn are screwed.
This will sure help big hardware vendors, though, as they can afford the signing process. Small upstarts will see this added cost and will likely go work in another market where they don't have to prove their integrity to the OS vendor.
The right way to do this is to let you, the user, decide, just as you do with secure websites. Let there be some common certification authorities (just as there are those installed in your copy of Firefox) but let the user add more and add more certificates for driver writers he trusts. (This would be done by the machine admin, so the owner of the machine gets the say, not his employee or kid.)