Even 3.2MP would be impressive to fit in the small space available, although unfortunately, I doubt the presence of the rear camera as much as I want it.
Anyhow, all this FaceTime talk means that the iPod's going to also be getting another high demand add-on: microphone. Apple is highly unlikely to force customers to put on the earphones with mic for using FaceTime as it is cheap to add on a microphone (component-wise for them). This also means easier to record voice memos/lectures, and "speakerphoned" Skype, which would be similar to the FaceTime experience. Yet all this means that to be able to listen to the proper voice quality of your FaceTime friends, Apple's going to need to do something else as well: enhance and improve the speaker that has existed since the 2nd gen.
Another note: the iPod touch is Apple's flagship mobile gaming platform (as claimed by Apple and portrayed through their advertisements)... so in addition to the bumped up performance (A4) and graphics (Retina), Apple MUST be adding in the Gyroscope, since this is a BIGGIE for games, and location-based social media (e.g. Yelp) on WiFi.
All this means that the iPod will be more similar to the iPhone than ever before.... things that it won't have will probably vary from Phone, Messages, Camera (maybe yes, maybe no), and GPS. Otherwise, it's an iPhone. WELL... someone's going to have an app for a camera if Apple doesn't (with the VGA front-facing FaceTime cam)... so that issue's almost covered. Phone and Messages - Pinger's textfree will take care of this, with free voIP calling with a phone number. Multitasking on iOS4 will mean that you'll always get calls. PLUS, GPS is already available with maps as "assisted location services"... so congrats... you have an iPhone on WiFi!
Here's the biggie though: Apple's either going to extremely impress with the listed features above (we're bringing this and this from the iP4 to the iPod!!!!) and maybe even more (a camera), or it may disappoint like the 3rd generation iPod touch with few updates (come on... Voice Control... after a year? That's all?) ... or it may be somewhat satisfying... being somewhere in between!
We'll see sooner than later since the event may "actually" occur later this month!