This is hardly definitive proof, but it's still interesting. A tipster has sent Engadget some snapshots suggesting that a new electronic device will hit Target shelves (Target is a department store in the US) on October.
The mystery item (its name is hidden) comes is six variations, with item numbers that match the iPad price points exactly. Additionally, screenshots from a Target PDA have the item placed in the store's Digitial Audio section, which is where the Kindle and iPods are sold.
Could it be the iPad? It's possible, but these weak images won't let us say definitively. We'll find out on October 3rd, the day it's supposed to go down.