if it is Wifi, then it is already pretty fast. Draft-N is the fastest almost standard out right now in terms of bandwidth.
Furthermore, my old CoreDuo MacBook actually has a SuperG compatible card. When I am in Windows, I connect to my router at 108Mb/s, so they are alreay pretty fast.
If you really need speed, then you should direct connect with either the Gigabit Ethernet adapter on your system, or FW800