From the Apple Site:
OG Ipod: Now that you can buy movies from the iTunes Store and sync them to your iPod, the whole world is your theater. With a 30GB or 80GB iPod in hand, those movies fit comfortably next to TV shows, new iPod games, podcasts, audiobooks, photo albums, and, of course, an entire library of music — up to 20,000 songs, in fact. Now starting at $249, iPod is a pocket-size prodigy.

Nano:A thinner design. Five stylish colors. A brighter display. Up to 24 hours of battery life. Just about the only thing that hasn’t changed is the name. In 2GB, 4GB, and 8GB models starting at $149, iPod nano puts up to 2,000 songs in your pocket.

Shuffle: The world’s smallest digital music player and just $79, the 1GB iPod shuffle lets you wear up to 240 songs on your sleeve. Or your lapel. Or your belt. Clip on iPod shuffle and wear it as a badge of musical devotion.