You clearly do not work in IT and you are just wrong. I don't know how else to say it.
If you get rid of Ethernet on a mac it becomes clear to the business industry that macs are not capable of being professional working computers. Most businesses have policies against using wifi on a private WAN because it's a security risk. Wifi is typically segmented on a different vlan which is tunneled thru a dedicated DSL line away from the network. The only way to get internet to actually do work (outlook/groupwise, shared files, access to your corporate application system, etc) is via Ethernet. That is a fact.
Also access points have limited bandwidth. Ya your imaginary 600mb/s is fast to YOU but that's all the bandwidth it has. The standard is actually 300mb/s. It's not a lot if you share it across 500 people. Compared to a 48 port cisco gigabit switch that are stackable that has a bandwidth of 96-104Gb/s (depending on how many fiber ports it has) per switch. That makes wifi use in a business impracticable.
Ethernet is not going anywhere. Wifi will never ever overtake the amount of bandwidth (and security) that a cisco switch can provide.
It would be a step backwards to get rid of a standard after just now being accepted in the corporate world. I would imagine that Apple understands that and will not be getting rid of Ethernet on it's professional line of computers.
edit:
Oh and if you actually believe that corporations are going to spend thousands of dollars on stupid adapters that fail after a year of travel you better think again. The amount of labor involved in showing users on how to use it, the fact that they get lost, and the logistics nightmare makes it not worth it in the corporate world.