Time Warner going digital???

I thought everything went digital years ago? I just got a message from TWC saying that as of some date in June their signal will be digital and an adapter will be needed if you plug the cable directly into a TV.

Now I assume this will not affect the HD TiVo's with a cable card?

But what about the non HD ones? My parents still use an older one, series 2 I believe. Will they need an adapter or is that machine going to be obsolete after the change?

Thanks