Actually, think about you DVD library, and remember the day you first got a 16:9 HD display? Remember when you popped that first one in?
I went from a 32" 4:3 CRT to a 40" 16:9 HD LCD. Almost the exact same vertical height. A DVD's image on screen was about 80% LARGER than my old 32" 4:3! Widescreen SD if you will. Lemme tell you, it's damn good AND FAR better than what I was used to on the 4:3. Essentially, the next step (getting to better resolution of HD) just isn't as big a leap as the step I just took by going to a 16:9 set.
Add in that folks at times forget about the filmmakers artistic vision. It can be made to look like nothing you might expect from additional resolution. Look at a film like Spielberg's War of the Worlds. I've seen it in HD and widescreen SD (from the DVD). You know what? Not a whole hell of a lot different. You have to watch quite closely AND only judge by certain scenes to tell which is which version.