To be perfectly bluntly honest, I think all you people who think letterbox-only (i.e. no resizing) is the way to go are on crack.
I still fail to understand how you can not see that having more of the frame available for the picture, and filling that up with carefully-crafted information derived from the raw data by someone looking at each scene and tweaking accordingly is preferable to having your TV scale it up like it scales everything else. I spend quite a lot of time on Doom9, where people are scaling up DVD to HD resolutions, and there is no question whatsoever that the end result is preferable to letting either your DVD player or your TV do the scaling. And these are people who capture anything and everything and convert to and from every format under the sun. There are guys there who know more about video than most of us will ever hope to know -- the sorts of hardcore video-processing nerds who can likely rattle off the mathematical relationship between YUY2 and RGB without consulting any references. I tell ya: if those guys figure upsampling in less-than-realtime beats the hell out of letting the player/TV do it, then I figure there's not much point in arguing.
Besides, pretty soon every DVD is going to be anamorphic (about 99% already are) -- so why would you want some oddball that isn't??