The Macs with 802.11n (draft 1.0) hardware are:
- Core 2 Duo based Macs (iMac, MacBook, MacBook Pro)
- Mac Pro with built-in wireless card.
Anything else doesn't have the hardware to make use of the increased networking speeds and range that 802.11n brings.
It's "C2D" for Core 2 Duo not "d2c" but that's by the by.