I definitely agree with your point (I myself have an iPod touch, which replaces my dead iP4). However, the problem is coming from Apple's financial economics model. The company needs to find something that would make the iPod touch stand out from the rest of the pack. If you look at music keynote last year at the Apple's Events website, the iPod touch (3rd generation, September 2009) was the number one mobile device in the world (even higher sales than the iPhone) and was praised. If Apple's newer products (iP4/iPad/iPod nano) are going to be killing the iPod touch, then they're going to have to come up with something extremely impressive, or else they'll lose sales/market audience. Certainly enough, mass-produced iPod touch sales are going to be considerable to Apple's profit evaluation model.
Definitely see where you're coming from. The iPod touch is technically marketed towards a younger audience, being Apple's flagship mobile gaming device, but as the first quoted post indicates (from aznguyen316), it's also used by adults who love Apple's idea of the smartphone, but don't want to be stock to AT&T's commitment plans. Either way, this year's iPod touch MUST be impressive... but it's got such a large market that it's going to be taking away some light from the other upcoming iPods (small touch screen/etc.).