Well, after a lot of searching, I figured out how to use wlanctl-ng, which is kind of ugly. I'm posting from my wireless card now, but I'm still curious about why the "easy setup" with eth0 has gone away and wlan0 replaced it. Here are the commands I typed to get it going:

# wlanctl-ng wlan0 lnxreq_ifstate ifstate=enable

# wlanctl-ng wlan0 lnxreq_autojoin ssid=hot authtype=opensystem

# wlanctl-ng wlan0 dot11req_mibset mibattribute=dot11WEPDefaultKey0=fa:fb:fc:fd:fe

# ifconfig wlan0 up

# pump -i wlan0

This sets up my DWL-650 to connect to the ssid "hot" with the WEP key "fafbfcfdfe"

-Tofer
p.s. oops...messed up a line in the first edit.