I tired of OEM deciding to save a few pennies and inconvience me by not providing it. RJ45 is and industry standard. Look in any IT infrastructure. A 1GB full duplex connection can blaze data to you NAS or Router shared HD. WiFi will never touch it and with full duplex the NIC's data is doubled to 2000MB/sec theoretical of course. I don't want a dongle (good ridence from the old PCMCIA card days of 3COM etc.

You still need to plug-in and external DVD drive for those intallation and burning requirements if if they take it out then supply it as a plug-in drive standard (not an option). Some ports become awkward to use when they're too small such as Micro USB, Mini was fine downsize with clear profile and robust to plug it in but not the micro port and I don't see the space saving there.

Buy and NAS drive or Router and you'll need a good Windows PC to set it up with the Ethernet RJ45 port. Joy and at double the price too. This just adds another Apple product to the list of becoming difficult to transfer files quickly. I-series devices without USB drive connection emulation for file transfer requiring mostly emailing attachments and the Macbooks going the same way soon enough it appears. Ideally I don't want or should need to carry any other cables or adapters/dongles than a patch cable, USB cable and my power charging system components. If you're into video's you may carry your own HDMI cable but most destinations you might need them would have them or you run down to a local store on your travels and pick it up. But they're light and non proprietary unlike a Thunderbolt to ethernet or other adapter.

Ports are important to me and one reason I never bough an iMAC. No eSATA to hang high speed drives efficiently and light years faster than Firewire. It was built into the machine already and a port on that big case could have gone anyware, but no. Apple does not want you to connect to anything that isn't or used to be unique to them.