On the MB Air, Ethernet is already a legacy dongle via USB. They can't fit a full-size Ethernet connector into the case, and it's probably the same issue on the new MB Pro 15". I figure, for people who really care, they'll buy a desktop base station of some sort, either integrated with a monitor like the Mac 27", or in a separate box, like Matrox, Belkin, and others are offering.

What I find modestly surprising is that the new machine is only supporting 802.11n, not the newer 802.11ac. I guess that chipset isn't quite ready yet.