It occurred to me that Jeff_W wrote in gmane.os.netbsd.help:
> Realtek, Rtl8139, M^?M^? (manufacturer 0x0, product 0x0) Realtek Semiconductor 8180 802.11b (ethernet network, revision 0x20) at cardbus0 dev 0 function 0 not configured

Hm, next time, I should pay more attention. It looks like this isn't a rtl8139
at all, but an rtl8180 which is being misidentified. the rtl8180 is supported
by the rtw driver.