I have to admit that I'm really confused why anyone cares.
The graphics card in question will probably cost a whole lot more to buy than a full standalone BD player from say Panasonic. The Panny will probably have playback just as good, consume far less power, be quieter in operation and won't need regular updates to whatever PC application is needed.
The only reasons I could think of the PC card are:
1. For someone who loves BD live and finds their PC does the job better. (does anyone actually look at those extras)
2. For someone with a shed load of ripped off hi-res movies, and I'm struggling to understand why anyone can be bothered with a 10GB+ download when you can hire BDs from Tesco for all of £1 a pop and be on the right side of the moral fence.