A lot of people have been waiting for this. So far the types of routers affected is pretty small. I think default passwords are the biggest problem. I discovered 2 wireless routers with default passwords and web admin open to the internet just the other day...
And of course patching routers should be easier. I doubt most people even think about it (kind of like network printers). And then there are all of those people with older routers that aren't supported by the manufacturer any more.
EDIT: Oops, looks like any linux based router (using mipsel) with weak passwords can fall victim.