Although I'm not in the market for one at the moment, it became apparent that I really didn't understand all the whoopla about HDTV, digital signal, or even the difference between buying LCD vs. plasma when thinking new TV until this holiday.
My extended family got together mid-month to celebrate a sibling birthday and one of the group gifts was a new flat screen TV. That is what started the discussion about the impending February 2009 date about the TV signal switch from analog to digital. This will be the biggest change in the "science" of television broadcasting since the early 1950's.
No, you don't have to run out and purchase a new set. Those of us with our old trustworthy sets will still be able to tune in. If you use a cable service you should not even notice a change. If you don't, you will have to get a converter box to continue using your old set.
Even when purchasing a new set, read the details carefully. The larger, higher priced models come fully equipped. The smaller flat screen TVs, especially in the 15-30 inch range will need an adapter added later.
So, we have some time to make our decisions, do our reading, and save our pennies before throwing out the old clumsy square black boxes. Here are a couple of websites that will give you some basic information without too much "science" mixed in!
Digital Television Consumer Corner
DTV Transition Q&A
Compare LCD vs. Plasma here.