I personally think that the new iPod Touch will have a major refresh this September. I predict that the Apple iPod Event will be held September 8th this year, since it is the day after the Apple Back To School program ends, and last year the iPod Event was held the day after the Back To School program on the 9th of September. Here is what I think the new iPod Touch will have:
New Capacities: Comes in 16GB, 32GB, and 64GB. No 128GB model this year since the iPhone 4 didn't get a memory bump. Probably next year.
New Prices: 16GB-$199, 32GB-$249 or $279, $64GB-$349 or $379
Changed design: Possible aluminum enclosure similar to the iPad's design, or something similar to the iPhone 4 but not made out of glass, but more squared off. We will most likely see an updated design because Apple doesn't usually stick to the same design for 3 refreshes straight, as we have seen with the iPhone 3G and iPhone 3GS which had the same design for 2 years but then dramatically changed with the iPhone 4 with it's new design.
3.5" Retina 960x640 Resolution display on high end 32GB, 64GB models, same resolution 3.5" display on 16GB base model.
Gyroscope
Front facing camera (Steve Jobs noted that there would be 10 million FaceTime "DEVICES" sold this year) Which basically means, that there is a possibility that the new iPod Touch could have a FaceTime front facing camera on the higher end 32GB and 64GB models.
Possibe Rear Camera (Sources say the new iPod Touch 4G could have the iPhone 3GS's 3.2MP camera, and I strongly believe that the new iPod Touch will have it because if it had the new 5MP camera, it would have too many features borrowed from the iPhone 4.
Better Speaker
Built In Microphone on 32GB, 64GB models
Released On September 8th, 2010.