Indeed it seems I was wrong. Read it here that it was dual core. Instead wikidevi states it is single core with two threads.
Is it because the wireless chips perform better?
Where can I confirm it is going to be supported? And when is it expected? I'm dubious about buying it since people reports having troubles flashing openwrt and while I'm open to experiment, I don't want to buy something that may or may not work. If it were supported by a stable release, I would have already bought it.
I'll try to see if I can find them. Unfortunately, in my country, ISPs bundle their offer with their proprietary all-in-one wifi modem/routers and so there's not really great availability of second hand wifi routers supported by open-wrt.