… for when you’re serious about being connected!
But seriously, I don’t see the purpose of this except for some cases where the machine could function as a internet sharing gateway as well. As far as I’ve gathered the purpose for dual LAN-connectors is for people “seeking complete network redundancy” but in my opinion this is just hogwash. Network redundancy would require two different uplinks as well, not just two cables plugged into the same NAT-gateway, because I seriously doubt most people have two completely different connections to the ‘net to use when distributing this load.
I never cease to be amused at the vaguely worded but impressive sounding crap computer companies put out today.
And yes, this is the rear of my computer, and yes – I do actually have two cables plugged in. It happened about two minutes before writing this, and as soon as I’ve published this I’ll probably yank one of them out.

I don’t use one of my two intergrated nics but its good to have just in case ;P Also there is a feature so you can combine them and get 2Gbit ;P Too bad not even an SSD disk can max a 2Gbit connection..
Bridging the two NICs is of course a possibility, but in reality it of course doesn’t provide any more redundancy, and in the real world no more speed except in theory. The weakest link of a chain and so forth…