Hi,
Have you done anything with these? I happen to have both (WR702N and WR703N) now. I got the 702 to use "for real" and it still has the stock firmware. I probably won't change it. I put the OpenWRT firmware on the WR703N and managed to brick it somehow even though I wasn't trying.
I added a serial port to one and I've learned quite a bit about u-boot, but I haven't tried to boot NetBSD. It seems that NetBSD on MIPS is broken unless you want to run NetBSD 5, so I figure it isn't worth the effort until NetBSD in general is fixed. I'm going to write a separate email about that.
John