I actually have the model you mentioned.....Toshiba 40H80....and I have loved it ever since I bought it back in November. I bought a widescreen because watching movies (DVD) is the main reason I bought the TV. I have it hooked up to Dish Network, and the picture is pretty good, but not spectacular. You can watch regular TV five different ways....
Standard gives you a 4:3 image and puts grey bars on each side of the picture....I never use this
Full streches the image to fill the TV.....I never use this for regular TV, but always for DVD's
Theater Wide 1,2,or 3 give various versions of stretch and crops to fill the screen.....I use 2, which just zooms the picture in and cuts off a small portion of the top and bottom of the picture......
If you are going to use this TV for mostly standard TV viewing, then I would get a 4:3 model instead.....If you are going to use this TV for primarily watching DVD's, then this is the TV for you....
If you do buy a High-Def TV, regardless of 4:3 or 16:9, then you will want to get a decent progressive scan DVD player.....I use the Toshiba 6200.
If you buy a rear projection TV, then you need to spend some time calibrating it......pick up Video Essentials or AVIA.....these are DVD's that walk you through the process. If you really want a spectacular picture, then have it ISF calibrated....but this is expensive.
The very first thing you should do when you turn on a brand new projection TV is turn down the contrast and brightness....these are usually set very high so that the TV will look good on the showroom floor, but these settings can damage a projection TV in no time flat......you can easily burn images onto the CRT's with these settings.
Anyway, hope my rambling helped you out a bit.....the one thing I love about a widescreen, is that they just look so damn cool compared to regualar tv's......I really don't even like watching 4:3 tv's anymore.....they just seem too cramped up to me
Good Luck!