It's weight they're prioritising, not thinness, if you're going to keep it the same width but make it taller and keep the same runtimes than you're going to have to account for the extra volume by shaving the depth or it's clearly going to be heavier.
That the runtime is actually improved* while jamming in 4G and a bigger hungrier display is pretty good.
My take, seems like a nice phone, not sold on 16:9, but I don't watch media on my 4, NFC seems like an odd ommision, TBT is long overdue. If it had a 3D display (as mentioned above), I wouldn't even consider it, IMHO 3D displays (all of them), are still as crap as they were the last two times they tried to foster them on us, I can't begin to relate to someone who would want that on a mobile device
Will wait until I have a hands on with one before I decide if its worth upgrading or cutting my contract bills instead.