TV Tuner Cards and HDTV

I was thinking about getting a TV Tuner card for my computer and I was wondoring would a TV Tuner card I get now be compatable (be able to revice the singles and stuff) when they switch over to HDTV in 2004 or something?

I doubt it. There's no way to add pixels (on the cards gpu) to the edge of the picture by software changes, nor can it recieve the extra signals that it must to get the better image.
Anyway, the picture would be difficult to see since HDTV has a different aspect ratio (it won't fit your monitor), so it will be only half the size of your monitor from top to bottom.

By 2004 you'll have gotten your $30's worth, and may not even have the same computer.

You got a point their...