New photos comparing a claimed next-generation iPad back panel to an iPad 2 offer further evidence that the device will be slightly thicker than its predecessor and sport an improved rear camera. In a wider-reaching roundup of iPad rumors, M.I.C. Gadget has posted a number of comparison photos, which claim to show an iPad 2 and a “confirmed rear shell for iPad 3 Wi-Fi + 3G model”. Notable in the photos is a more gradual taper to the edges…