BJ,
Sorry for not following up my earlier advice sooner but my 'puter has been down (grr)!
Most (if not all) widescreen TVs have a button to switch between various options, as I mentioned before my Philips is by no means a top-end set but I have the following : Widescreen, 4:3, Zoom 14:9, Zoom 16:9, Subtitle Zoom, Super Wide.
The "Super Wide" setting on mine is a "smart" setting, it optimizes itself for whatever you are watching. I find that with terrestrial broadcasts I get no black bars (either top/bottom or side/side) and the picture is in proportion. I seem to recall that even my friend's Goodmans set has a similar option, but bear in mind what I said before about getting what you pay for (his picture quality leaves much to be desired).
I can only assume that the sets you saw in-store were on the default setting rather than the "intelligent", just checked on mine and it does indeed give black bars top and bottom. This is entirely user-correctable.
I stand by what I said before - get a widescreen, the varying transmission standards that are causing the current confusion will all be standardized when analogue terrestrial ceases in a few years time. As I said, I argued till I was blue in the face that I didn't want to get rid of my "square" telly, but now I have, I wouldn't go back.
