This that the Mobo you plan to get for your build ?
at curious stage atm, cuz its a few$ cheaper than crosshair in my local store
To me it wouldn't matter since my internet caps out at 130Mbps on a good day and I don't have a NAS.
a 2nd LAN port in general is something I currently don't have a use for, but I understand that some people actually do.
Since you're asking I take it you're having a hard time thinking of why you would need that feature. In which case I would suggest acting like its not there and then asking yourself if you like the mobo. (the mobo seems fine to me, just trying to help you not get sucked into something that to me is mostly marketing hype for the avg user at this point in time)