The battery might last a day if you don't open mail, Safari, Photoshop, FCP, Logic, or forget to stop the mds processes etc, randomly draining the battery with no outlet in sight, or almost any other app. Have fun with that. Or stick to an iPad.
Not expecting To charge THEIR MacBook maybe, but not MacBook Pros. You run a pro app and that juice is gonna get sucked hard and those fans gunna spin.
USB-C/Thunderbolt is Jony's wet dream, and he's not going to mess it up with different ugly ports. Moving all that **** outside with adapters, cables and boxes is the users problem now. Sure more stuff will eventually get USB-C'd, but at your expense and/or with questionable quality and reliability.