I've been watching the DD-WRT forums for updates on the switch driver for the WRT160Nv2, and it looks like the code (in some form) has been released. You can find it here.
I'm just wondering, being a moderate linux user and programmer, if it is just as simple as cross-compiling this as a linux library module (.so) and loading it with the linux kernel (modprobe?).
Although I used the word "simple" it is not so for me, since I have no idea what compiler flags to use, or how to make the file "stick" in the filesystem on the device, once compiled, or even how to set up an environment for cross-compiling. (hey, I said I'm only a moderate developer, and even less so on Linux) For all I know, it may even need to be compiled into the kernel.
So, if anyone can point me in the right direction, I'd like to try to get Tomato USB working on this device. I don't have access to the device at this exact moment (it's being used in a rental property of mine), but I'd like to do anything I can to help.