Best Buy is selling 30" HDTVs for $499 not $900.
HDTV is going to be the only over air standard as of 2009, what makes this dealine different is that the FCC has is looking to sell the old analog spectrum to wireless companies for big bucks so with everyone knowing about money being a motivated, this time the change will happen.
There will be convertor boxes for older TVs, but being active electronic devices expect to pay around $100 for them at least for a while.
What is being missed here I think is that in addition to HDTV there have been numerous advances in LCD and Plasma technology that allow for higher quality and "thinner/lighter" TVs to come out. For example my 56" LCD projector TV (that has a greater than 45 degree viewing angle) weighs less than my 32" tube TV.
The LCD/Plasma screens also typically give a better picture for good old analog signals.
Chances are if you are still watching on a 19" screen than viewing movies/TV isn't important to you and you're better off waiting a while for prices to come down. For the rest of us the extra money is well worth it.