A current, there is no solution for PCI based TV tuner cards for OS X.
With that said, there are other solutions using other methods.
ATI has a USB edition of their TV tuner that is supposed to work with OS X.
Formac at current still have not decided to bring support to their customers that have the Formac ProTV Stereo PCI cards and basically to us that if we really want TV on OS X, we need to spend an additional $499 (last I checked) to buy their ProTV Studio, which all-in-all looks like a good product but is just too expensive to just watch TV (Plus it's Firewire).
According to BTV, in order to use their software you still need valid video drivers for the hardware, BTW is not a substitute for missing OS X drivers.
I really think Formac needs to stop being cheap and support the new operating system fully and provide OS X support for their ProTV Stereo TV Tuners. I pulled mine out and vowed to never use it again unless they add this support.