The Dell's wireless is a 802.11g card (so the antenna hangs out and uses up the card slot). The Mac's is 802.11n and is integrated leaving a free card slot.
Oh, and Dell sells this computer for $1900, not $1600.
The specs look close superficially, but dig down and the machines aren't even close in terms of features and performance.
The Wright Bothers weren't the first to fly. They were just the first not to crash.