Well, at first I misunderstood that we would share the PCI SSIDs together with enum items. Sharing only the enum items doesn't give much improvements. Sharing the card database may do, though.
So, I see Trent's point. The merge work wouldn't pay for the benifit by sharing only the enum id, not the card database.
I like the idea of sharing the database. This probably will mean that snd_bt87x would be dependent of bttv driver (or a bttv core driver). This have the advantage of helping also to fix some conflicts with dvb bttv driver.
This change, if agreed by all, will require some extra work. The better is to commit Trent's patch first. Then, we can work on re-designing bttv driver in a way that the database can be shared, without needing to load the entire bttv drive.
Probably, we should first push the bttv v4l2 series of patches before starting this change at bttv.