If said screen does increase in size, then there's no doubt they'd up the resolution. Even if it doesn't, I think it's pretty certain the retina display will come to fruition on the iPod. It serves the purpose of pushing developers to update their apps to HD graphics.
I'm guessing this:
(iPod Touch)
128 GB (Eliminating the iPod Classic, this or next year)
New Design to match iPhone
Front Facing Camera (A back camera, I doubt. It's not Apple's style to do everything at once)
Retina Display
(iPad)
128 GB
Same Design
Front Facing Camera
A back camera is highly doubtful.
(iPhone) Early 2011
64 GB
Redesigned Antenna
To my knowledge, this would fit how Apple rolls their products out. There's a reason the iPhone 4 didn't launch with 64GB. If it had launched as such, there would be no incentive for people to purchase the iPod Touch, and it would also diminish iPad sales by a small margin. This way, they can introduce the 128Gb iPod Touch, place the focus on this and the iPad, then launch a 64Gb iPhone, therein spreading the focus.