I know that this thing has been discussed to death in the media, so I just wanted to make a short post about what I think sums up its design: wireless operation. The one thing that I feel really makes this point is the timing of Apple's current OS X beta. This MacBook is unworkable without iCloud Photos. It's unworkable without AirDrop, it's unworkable without wireless syncing and iCloud Drive. This is clearly, to me at least, the culmination of the last several years of OS X development. It's continuity, it's SMS relay, it's handoff.
The best part is that none of this is unique to the new MacBook, any Mac with low power Bluetooth can take advantage of all of these features.
The new MacBook's product site has a whole page dedicated to wireless operation. iCloud, AirDrop, AirPlay, AirPrint, Personal Hotspot, Time Machine; I use these things pretty much daily myself. The only ports that see regular use on my MacBook Pro are power and Thunderbolt for my external display. If it weren't for my gaming habit I'm pretty sure the new MacBook would be ideal for me.