The storage I/O stack of the Windows Server family has been described in some detail. Beware, though, that the storage stack does not yet cater to multiprotocol devices.
In an effort to improve Windows reliability and security, the Microsoft model for signing and certifying drivers is continuously evolving. Vendors are advised to keep abreast of the updates in this area by certifying drivers. The Microsoft Web site in general and http://www.microsoft.com/hwdev/driver/drvsign.asp in particular are good starting points.