Dinny, I haven't seen too many cases for the new Touch yet and I don't think they'll be coming as quickly as they did for iPhone 4. Hard Candy has some (iPod Touch 4G Cases, Covers, and Skins | Hard Candy Cases), but they don't have holes for the speakers on the bottom (i.e., using FaceTime would be difficult).
As for a Defender case, prepare to wait for a long while considering how long it took Otterbox to release ones for iPad and iPhone 4.