How about tru2way

It looks like it launched a year ago. Anyone know if this made any headway in the market? I'd have to check if Comcast offers this and what the charge is. I'd like to avoid an additional monthly fee for this second TV.

A Windows 7 machine with QAM would work, since I'm ok with only having broadcast channels in HD on this TV (I can stick with downstairs for sports).

If I thought it would work from where I live, I would consider an antenna and OTA HD for upstairs. I believe cablecard is free in my area though, which is why I started with that as an option.