How is this news? I think it's well known that the new Retina-MBPs have made some hardware-upgradeability sacrifices in exchange for portability.
Personally, while I understand why thinness might be great for some, I don't understand how they can sacrifice essential features(exchangeable components and ports(GigE)) for a few mms or grams on a laptop that is clearly marked "Pro". I'd think that exactly pros would be the ones that would make use of these features the most.
* Finally, if it really is a problem, buy the Thunderbolt to GigE adaptor.