Engadget mentioned the viewing angles weren't as good as the iPhone 4s. Many are guessing it's not an IPS panel based on hands on comparisons. Unlike the iPhones, which is heavily subsidized by the telecos, Apple needs to make a profit with the Touches, so cheaper components are necessary.
Apple has also been touting IPS screens--iPad, iMacs, Apple Displays, and iPhones, but this was missing in their marketing materials for the new Touches.