One can see Apple did used a 802.11n Wi-Fi card with only two anntena connectors instead of three for the previous ones. The unused third one got protected with black tape.
From now on, Apple has a single type of wireless card for the notebooks and the Mac Pro.
Technically, if this could result in Wi-Fi signal reception problems or even output issues, we didn't notice any significant differences between the old and the new cards when we offered our Core Duo computers a 802.11n upgrade.
