“Reliable sources” near and dear to Think Secret say that new iPod minis are going to come out soon with color screens and larger hard drives:

Highly reliable sources have confirmed that the next iPod mini will gain a full-color active-matrix TFT screen while the form factor will remain largely unchanged. The color screen will be able to display colors clearly and brightly regardless of ambient lighting, even outdoors in direct sunlight. The new screen will be about the same size as the current iPod mini display and will sport a 176×132 resolution.

Damn, now I need to buy an iPod mini to go along with my 4th-gen and shuffle.