Here are some updates:.

The orinoco card I have was tested successfully with OpenBSD 3.5 but on 
an older laptop model. I never got this card to work on NetBSD (1.5 / 
1.62). On the Amilo laptop I'm testing wireless with, OpenBSD fails 
(stucked during boot) and NetBSD 2.0_RC4 recognizes the card and brings 
it up. Nevertheless, no way to establish ip connectivity (looking for 
mac address issue right now). RF is ok and wiconfig wi0 lists the 
correct parameters (SSID, chanel, ...).

Christian Goetz