Not a bad idea, it's always nice to think your prepared for whatever, even if it never pays off.
It's funny about TV's, when I bought my HDTV I just HAD to buy component cables for all my old game consoles, but since they look pixelated and rarely have a widescreen option I keep my old TV hooked up.
Meanwhile I only have 1 HDMI cable, so when I want to switch between the 360 and PS3 I'm usually too lazy to pull the TV out of the corner to switch it back. It's a sad state of affairs.
I hear you about the old TV, in most games the text is so small it's almost impossible to read unless your viewing in HD.