iFixit found a larger front-facing camera in the fourth generation iPad. 

iFixit is focused on tearing apart Apple products this week. After a complete teardown of the iPad Mini, they've cracked open Apple's latest version of the iPad. 

We were most interested in seeing the new front-facing 1.2MP Facetime HD camera inside the iPad 4, which replaced the .3MP model in the iPad 3. The new camera can shoot 720p HD video and is slightly thicker (an extra .4 mm). 

iFixit also took a look at that new Lightning connector on the fourth generation iPad; you can review the full teardown on the iFixit site.