It occurred to me that iMil wrote in gmane.os.netbsd.devel.network:
> A simple wiconfig ifX -D used to work without up'ing the interface with 
> the ath(4) driver and my ral(4) backport on NetBSD 2.0, can anyone with a 
> ralink cardbus or pcicard try out the scan mode ?

I'll have a go at this, but I'm extremely weary about it. Your original
backport works perfectly on my laptop, current's ral is only good at 
generating kernel panics, so it seems.

ral0 at cardbus0 dev 0 function 0
ral0: 802.11 address 00:50:18:32:47:6e
ral0: MAC/BBP RT2560 (rev 0x04), RF RT2525
ral0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
ral0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36M
bps 48Mbps 54Mbps

lspci has this to say about it:

03:00.0 Network controller: Unknown device 1814:0201 (rev 01)