A comparison between the two devices has been made by iMore.
In terms of display, the iPhone 5 and iPod touch 5 share the same 4-inch, 16:9, 1136×640 326ppi IPS (in-plane switching), in-cell display, whereas the iPod touch 4 had a decidedly worse display than the iPhone 4 or iPhone 4S, the site writes.
The iPhone 5 comes with a two-tone back, while the iPod touch features an edge-to-edge aluminum panel, which is different from the iPod touch 4 but similar to the iPod touch 3.
The iPhone 5 and iPhone 4S are equipped with 8 megapixel sensors for their rear-facing iSight cameras. The iPod touch 5 features a 5 megapixel sensor, similar to the iPhone 4.
The front-facing FaceTime HD camera on the iPod touch 5 is the same as the iPhone 5′s, capturing 720p video, which bests the iPod touch 4′s VGA (480p) FaceTime camera.
The iPod touch 5 and the iPhone 5 both lack the phone mic and the grid design, but also share similar layouts now that the headset jack on the new iPhone was moved.
Another similarity between the two devices is the use of the new Lightning connector at the bottom, making them thinner than the iPod touch 4 and iPod touch 3.
As far as the form factor is concerned, the curvature on the iPod touch 4 and iPod touch 3 makes it difficult to estimate but the site writes that the iPod touch 5 appears to sport a flatter design, more reminiscent of recent iPhones than iPods.