I've been thinking about this for quite long and I always picture an hypothetical future iPod Touch to have a 3G/4G connectivity added to the current Wifi connectivity.

Is the iPod Touch going to be an iPad Nano? Or will it continue to exist as an "iPod" brand?

I just don't see how could they advertise an iPod Touch with 3G / 4G connectivity without it being an iPad Nano.

What would differentiate a 3G/4G iPod touch from the iPhone? As far as I know the iPod touch is just an iPhone with last year's CPU, no earpiece, no 3G/4G, and no compass/GPS.