Yes there is a time limit for analog I believe if I remember correctly from reading about it on an HDTV forum. I believe eventually by a certain daye all tv is to be HDTV not sure of the dates should be easy to find.

When you actually watch HDTV programming on an HDTV set it will blow your mind, the picture is unbelievable it looks like the screen is not even there and that you could reach out and touch the people/places/things on the screen. I only have two HDTV channels presently, one being HBO and I find myself rewatching even bad movies just to be able to watch them in HDTV. After watching an HDTV program if I watch a movie on DVD right after the picture from my progressive scan DVD looks all grainy and rough