dk* drivers on NetBSD 5.0 (beta)-install

Hi folks,

I am trying to install NetBSD on my new Late2008 MacBook (aluminium  
case). While I've managed to make space for a decent partition and to  
install rEFIt, the install kernel will not allow me to copy the code  
on a dk wedge: I correctly get wd0, dk0,1 and 2 messages but I cannot  
choose anything else than wd0 to install NetBSD on.

The dmesg is interesting, many new options introduced by the Nvidia  
chipset are of course detected but not configured (there is also a  
"coprocesseur" ACPI id, probably in relation with CUDA), but some seem  
to work, ex : video0 for the built-in Isight.

Does anybody know how to get the kernel properly copied to dk2 instead  
of wd0? Shall I use a custom Install kernel? Anything else?

Thanks,
Vincent