802.11n macbooks ?

[Lodge family]

Hi All

I have read that the first macbooks (core duo) cannot use 802.11n,  
but new core 2 duo machines will be able to.
Is there an airport card availiable or going to be made availiable so  
that these macbooks can use the extra speed and range.
In other words are these early macbooks going to be limited to  
802.11a/g speeds

Thanks in anticipation
Rob