From the Capt. Obvious department, if you're shopping for a new HDTV, and you buy a widescreen TV (there 4x3 HDTV's also, which this site fails to mention), even if the size is listed as the same, it will be a few inches shorter in height. They've got a chart to make sure you don't actually end up with a smaller (height-wise) TV than you had before.
Of course, you'll probably be gaining quite a bit of real estate when you watch widescreen formatted programming like high definition broadcasts or DVD's, which in my opinion is a lot more important. I know I'm looking at my 4x3 32" Sony with a questioning eye now that I do all of my gaming in 1080i. I suppose especially for people who might not be getting high definition broadcasting right away (like 50% of you), the last thing you would want to do is spend the money and look at a smaller picture, so consider this an FYI.