The Mac version of SageTV was just released:
http://sagetv.com/sagetvMac.html

It looks good, though the details are sketchy-- it's not clear what tuners are supported or if it can handle clear QAM. I'd also like to know if the 3rd party commercial skip plug-in will be made Mac-compatible.

Still, this is promising news. Any thoughts?

Unless something has changed in the last couple of weeks, it supports a single analog ATI tuner. HD Homerun support would be nice, but I believe it requires support by the developers of the HD Homerun as well as a plugin architecture to be implemented by the Sage developers.

Sage is also selling the software with a USB tuner. It is the Hauppauge myTV.PVR USB TV Tuner. I don't know which chip this tuner uses, but it might be interesting to find out. I found this on their site, btw.

In the list of system requirements the only Mac tuner supported is the Hauppauge EskapeLabs myTV.PVR.

http://sagetv.com/requirements.html?sageSub=tv

Still, on the Sage Forum the developers strongly suggested that they would get some HD support in the product, and it's hard to imagine they would do all the hard work porting the program only to leave it crippled by lack of device support.

So, I'm hopeful that HD support will be forthcoming, including the HD Homerun. As an ethernet device, shouldn't it be fairly easy to support?

Firewire support would truly be great