Briefly thought I had a chance at setting up an IPv6 tunnel from the router, since I got root on it. (Through the long and arduous process of thinking "Huh, I wonder if the password is just the username?". Turns out, it is. The wonderful world of security on embedded devices.)
Turns out, no; it doesn't have IPv6 support at all. (And I don't think I stand a chance of recompiling the kernel, repackaging it, reflashing the router and having a working device at the end of it. :)
Nor does it have tunneling support, although since it doesn't support IPv6, it's a bit of a moot point; the only reason I want the tunnel is so that I can have IPv6 support. (It remains to be seen whether or not native IPv6 is available; I can't check with the router since it doesn't support it, and my ISP won't answer any queries about it.)
Looks like I'll have to find a low-power, less-restrictive Linux (Or BSD) box that can play router, if I want anything more advanced than what the little white box gives me.
Ho-hum.