Actually the end of analog TV broadcast is Feb 17th, 2009. After that date, consumers watching TV off the air will need a converter box for their analog TV (or new TV). Converter boxes are showing up on store shelves and can be purchased for almost nothing with the goverment-sponsored rebate.
"DTV" doesn't necessarily mean HD. SD content can still be broadcast digitally (ATSC standards).
Cable and satellite services must convert their off-air reception equipment to receive DTV by Feb 17, 2009 so as not to disrupt their customers. This most likely means that any HD content will be down-converted to SD at the reception point so existing distribution networks and channels can still be used.
I agree. No reason to wait.