That's a good point...I personally use the digital video recorder with Direct TV, and have not recorded on videotapes in years...even compressed digitally, the quality I find is better than video tapes and the ease of programming recordings is so much better. I know people who are recording off-the-air HDTV onto digital hard disk recording systems...I think purely digital recorders are the only real thing for digital TV recording.
I have not looked too much into the set top HDTV/digital TV receivers but they appear to be a specialty item: here is one I found that may be the most inexpensive:
http://ultimateavmag.com/hdtvsattuners/1104vinc/