But there's much more than just TV shows and 16:9 downloads. I (and many others) load lots of DVD movies on the 5G, and most of them are 'scope! Small, but watchable on a 5G 'Pod. But on a 2.40/1 6G such as I suggest, they'd be spectacular! And 16:9 on that screen would still be huge, with 4:3 much larger also than on the current model. So it's a win-win situation all around this way!
I was a theatre projectionist for 20 years and "constant height" is the way to go---and especially is this true on a small, handheld device. Black bars mask the sides ONLY, as needed, depending on the aspect ratio being viewed. Apparently I'm not the only one who thinks this way. On iLounge you'll find several mock-ups of this type of iPod in their photo galleries. Also, Apple itself, in their patent application for the "rear touch surface control screen" device shows the iPod as a CinemaScope model! So HOPEFULLY, they're already working on it! Don't worry, you'll LOVE it!