Perhaps with 2 fans (vs the 1 in the 13" models) and the larger 15" body cavity, they could fit in the 35W i7-3612QM CPU that people are hoping go into the redesigned 13" MBP. I have no idea if it's possible lol, i'm just kinda writing out loud. I guess if it's not possible, they could also just take an i5 35 W Duo-core and underclock it so the TDP goes down to fit it into the 15" MBA but still have a higher frequency than the 13" MBA. Anyone else have any thoughts on which processor would go into a 15" MBA?
MacBook airs have small batteries so I don't think a 35W processor would really work. They will just wait until the ULV processors are released.
If ethernet is the only stumbling block to thinness it could easily be handled. Just make a "mini-ethernet" port, just like the mini-DisplayPort and throw in the adaptor.
Or use a USB -> Ethernet adaptor like they currently do? That is slow but I assume USB3 will fix that? Ethernet to thunderbolt is definitely possible but it would have to daisy chain.
I really wouldn't be surprised if the ethernet port disappeared, I use it everyday but could live with an adaptor.