Naturally, the new touch will run iOS 6, so you'll get Facebook integration, iMessage, AirPlay Mirroring, and all that goodness, too. And the touch now supports Siri, the digital assistant first introduced with the iPhone 4S.
The new nano is in some ways a throwback: Video is back, and it has a bigger screen.
That display is a 2.5-inch Multi-Touch screen, the largest display ever built into a nano; it supports widescreen video. It adds a bunch of navigation buttons: There's a home button now, which gets you get back to your home screen quickly; and it has buttons for controlling volume and for playing, pausing, and changing songs.
Like the touch, the new nano is thinner than its predecessor (5.4mm vs 8.78 mm). It, too, comes in a range of colors (white, black, purple, green, blue, yellow, and red/pink).