It may (now) be wishful thinking, but I too think the 3G rumor could make it. iOS5 is heavy on the iCloud & iMessage stuff. That practically begs for anywhere/anytime options to connect to the Internet. It seems "less" to limit iCloud & iMessage to only when one can find some wifi.
As such, I'm still believing (maybe fantasizing) that the iPad 3G data options and on-demand 3G plans make it to this new iPod. Yes, that would be one more step toward it being an iPhone but no more of a step than what already exists in the iPad 3G (since Gen 1). The iPhone would still have plenty of features to distinguish it from this iPod, so I don't see the perceived "threat" (to iPhone sales) that some imagine; instead, I see those that can afford an iPhone and iPhone plans still buying a "real phone" and those that can't/won't NOT necessarily buying someone else's 3G device and getting locked into someone else's app store.
I think there are specific markets for this iPod with 3G data concept... markets that are unwilling to pay up for the 3G plans hooked to an iPhone. Apple should not let those markets go to Android and/or mifi options (for cheaper 3G options than iPhone). Some of those markets will be buying their first "real phone" in a few years. If they own a bunch of iTunes apps, that first "real phone" will be the iPhone 7 or 8. If Apple ignores that market such that they buy Android, then they'll have a bunch of Android apps when shopping for their first "real phone".