um... I got rid of cable a while back. I've been using digital Over-The-Air, and just stealing everything else off the Internet.
That said, as long as the box you get from Comcast outputs analog, you can record it with a tuner, and as long as the box accepts remote frequencies, you can use a blaster to change the channel on it, right?
Hauppauge even makes a tuner that will take high-def component video and let you record it. It's external.
The point is, analog cable is dead. Comcast can't make money off of it anymore. If you're gonna pay at all, you gotta live with the Terms of Service. I just told Comcast to take their service where the sun don't shine, but that's me.
It's not like DirecTV or Dish Network don't make you get a box... so, I'm not upset, but plugging your tuner directly into the wall and getting an analog signal into your tuner is done. Comcast has just been itching to flip that switch so they can rent you a box and control your subscription, then charge you for the experience.
My recommendation is that you get whatever box they're offering, and hook an IR blaster to it and find some way to get analog out of it into your current tuner.
Or just buy their DVR, and be done with it.
Or just get a big antenna and a lot of hard drive space.