Hello,
I also have one of the wave-p cards with the philips saa chipset.
I had some limtied success with the reference drivers which you can find on google however the machine bluescreened after a reboot so i dont recommend it.
I have also spoken with wave-p, guy called Ray, nice guy... He confirms that theres no WDM drivers available and its not planned however he did say that the card will have an api available at some point.
For the time being were stuck with the sorry excuse of software that it comes with.. Well not me.. im working on a refund from scan atm.