Still the best interface FOR MUSIC, IMO. I find it MUCH easier to navigate a library with the scroll wheel than touch screen, especially on-the-go. The wheel provides tactle feedback, the screen is just a solid slate. I listen in my car, and I can quickly choose new songs while waiting at a stoplight. iPhone/touch is a great multi-function device, great interface for being flexable enough to do practically anything well... but for music, the click-wheel is perfection.
I've had an old iPod 5G for over 5 years. half the pixels on the screen are missing and the thing is full of dust, but I'm going to make it last as long as I possibly can, and then get another one on eBay if Apple drops the classic.
Funny though, my favorite interface ever was the old 3G with buttons above the solid wheel. I liked having the separate buttons that I could feel. And it was the only iPod with no moving parts (save the hold switch). But the click wheel has been great too.
And for those of you who are arguing against having a giant HD capacity. You must not know the joy of "sync it and forget it". Sometimes it's great to have instant access to suddenly be able to listen to that tune you haven't heard in 4 years. Back when I had my 15GB 3G, I remember when I reached my capacity, suddenly syncing my iPod was a chore, I had to go through and decide each track I wanted to listen to, and then there were numerous times I was out and about and I'd think, "gee, I really want to listen to that... nope, I didn't put it on today". I was SO HAPPY when I got my 60GB 5G. I keep all my music really organized too, all 400+ albums.