Retina display
front facing camera (maybe also back facing, but if both, only vga, no pictures)
gyro
a4
n-wlan
No other new features will be coming due to the pricing. No ram increase, no led flash, no picture taking camera, no design change, no memory increase, no 3g, no battery life, etc. pp.
A price increase would lead to cannibalization through iphone and ipad and because the production cost are usually around 50% of the retail price. My estimated calculation is around 150$. There might be a chance of more ram, if there is a back facing cam as well, because this is the reason for higher ram in the ip4 compared to the ipad.
So there are two options for apple, either it has a slight bump in memory size for the entry level ipod and uses the current 3g model for the 199$. Or it will still have the 8gb memory but the same features as the higher priced models, for an slightly increased price.
Considering that the current entry level iPod is a 2g with the same memory size i think its very unlikely that the new entry level iPod is going to have those features, it would be a huge leap and manufacturing costs would be around 120$ leading to an retail price of at least 230$ or a change in apples price policy ha. On the other hand the differences between the entry level iPod and the pricier ones would obviously be recognizable. Currently its "only" a faster processor and more ram.