I've been running an SVN version of Kamikaze on a D-Link DIR-615 (hardware revision C1) for a month or two and I decided to pop the cover off to take a look at what's inside today.
It appears that the D-link DIR-615 rev C1 has a place for a USB port, various components for the power supply to be soldered, and two spots that look like they need to be bridged for the USB data pins, but they are all unpopulated. There's even a cutout in the plastic for it, so no dremeling would be required, one would only need to cut a hole in the sticker covering the back with an x-acto knife.
I have a few questions, though...
1) Has anyone else noticed this?
2) How hard would it be to get the USB port hooked up and working? This router runs off of a 5 volt power supply, unlike most that use 12 volts, so I'm thinking that the power supply circuit doesn't need to be too complicated.
3) How hard would it be software-wise to support this USB port? Do other routers based on the ar71xx/ath9k chipset have USB ports already? If so, does OpenWrt Kamikaze support the USB port on those routers?
I think USB would be very useful on this router because it has only 4MB of flash even though it has 32MB of RAM. (!) It would be possible to stick extra stuff on a flash drive that won't fit. (4MB is too small for a useful jffs2 partition.)
If I decide to try to hook up USB on this router, I'll post my results (including pictures) for anyone else who is interested in this.
Here are some pictures of what I'm talking about: