LTE based phones seem to require significantly larger batteries than than 3G phones, and 3G uses more battery life than wifi (the iPhone 4S gets 9 hours browsing on WiFi, and 6 hours browsing on 3G according to Apple).
So basically, the numbers don't really add up. It seems like the battery life gap between WiFi iPad and 4G iPad should be significantly larger than the WiFi iPad and 3G iPad, but instead it has the same gap.
Also, I'm not convinced the retina display needs significantly more power than the non-retina display. There are more pixels, but AFAIK the biggest power draw is the actual backlight, which is the same 9.7" as it has always been. The cpu/video processor would need more power of course, and maybe the backlight is brighter (higher pixel density might also be less transparent?).
There is something inaccurate about apple's numbers, it would be nice if someone (i don't have the right setup) would do an in-depth battery life test.