Will Sage TV (or any capture cards) support reading non-over the air HD content? I think as of about a year ago capture cards could only read unencrypted signals. (perhaps I'm mixing over-the-air with encrypted incorrectly here).
Johnny
Yes you can now record encrypted HD signals via the Hauppauge HD-PVR device. You connect it to your STB (cable or satellite) via component video and the HD-PVR will record the HD signal. It also passes through the component signal in case you wanted to connect it to you TV.
While this type of recording does introduce a digital (STB) to analog (component cables) to digital (recordings by HD-PVR are digital) conversion process, the results are still excellent. It is also one of the only component capture devices out there currently (at least in the consumer market).
So you can hook the HD-PVR up to any device that has component outputs (cable STB, any satellite providers STB, a Blueray DVD player, etc) and record the stream in HD quality up to 1080i.
This is new this year, and SageTV is one of the only software packages that officially supports the HD-PVR. In fact, the Hauppauge site only lists two third party software companies supporting the HD-PVR. SageTV and the default software that ships with the unit. That's it.
I have a HD-PVR and it works well. I actually have more problems with my satellite losing signals and therefore missing recordings than I have with the HD-PVR.
I also use a Sage HD extender to play these HD-PVR recordings. They are h.264 format and require a pretty robust machine to play them back. Most people who have problems with the set up are trying to play these files on a local computer. This is so cutting edge that many systems just cannot handle it IMHO. Between sheer CPU processing power and the correct set of codex, some are having problems. The Sage HD extender handles these files natively and few people have problems with that set up.
EDIT - Changed max recording resolution to 1080i (thanks Dave for pointing out my error).