Something just hit me.
I think the 6G HAS to be a widescreen/touchscreen and large capacity. Why?
Remember how people were somewhat let down with the 5.5G iPod, being that it only got a slight bump? My guess is that Apple has had the iPhone iPod all along, but couldn't release it because the iPhone wasn't out yet. If they released it last year, then everyone would be clamoring about the touch interface and widescreen in the iPod rather than in the iPhone. Once the iPhone was released people were thinking "Damn, what if they released an iPod like that!" Sure, the iPod would've sold amazingly if they released it a year ago, but I think it would've made the iPhone look a little less attractive. In releasing it the way they did, they built massive hype for the iPhone and will appease everyone who wants the large capacity, phone/internet-less iPod.