I didn't realized until now that the
Ethernet port is gone. I need that! That might actually be the main and only reason for me to not buy this. How sad, I really like the device otherwise.
Note: the ethernet chip _is_ present. In this article (anandtech) they look at Gigabit Ethernet performance and benchmark it at 925-928 Mbps - using the _Thunderbolt_ adapter.
Over at the iFixit teardown (step #13), you can see that the ethernet chip is present on the I/O board:
"Broadcom BCM57100 series Gigabit Ethernet + Memory Card reader controller"
I'd like to see a teardown of the adapter. My understanding of thunderbolt is it's not going to carry ethernet signals. There's another ethernet chip in the adapter (I think). The one on the motherboard is there primarily for the smart card reader and because it allows Apple to use the same chip on the laptops that do have ethernet jacks.
The ethernet port takes up 100% of the edge thickness of the previous generation 15" MBP. Also, I'd guess that something like ~5% of users take advantage of it on a regular basis.
So why would Apple let that keep them from making the device thinner? If you really need it, pay the extra $30 for the Thunderbolt ethernet adapter and call it a day: http://store.apple.com/us_smb_78313/product/MD463ZM/A
The ethernet port, much like the optical disk/Firewire is gone forever from Apple laptops. I use an ethernet cable at home/work with a permanently connected dongle, and carry one in my bag while travelling.
It's never been a problem, and, as soon as they start rolling out 802.11ac, I expect you'll have even less need for one at home/work (though may still be useful in hotels/remote offices without wireless)
I only use wired Ethernet on my laptop at work, so I would look for some kind of Thunderbolt dock if I got one (like the Belkin one coming out in September [1]). They're really pricy at the moment though so I hope we see more competition leading to cheaper devices in the Thunderbolt device area soon.
I was thinking of going that route, but now I wonder how long it is going to be before a Retina version comes out... Also, the Thunderbolt display doesn't have an eSATA port so I'd still need a converter and even the standalone ones still almost cost as much as the docking station I linked...