Did you ever wind up using the USB port, aurbina ? Seemed unneeded to me; if you prepare a good, organized ROM collection once, load up your microSD card from your PC, you're set. Occasionally when there's a homebrew freebie or something, then you'll have to eject it, load it at your computer and add the new ROM(s), etc. I just thought the lack of frequency of needing to reload it with new ROMs didn't much justify the USB port and you can get a SD-to-USB box for $4+ bucks nowadays from certain computer stores or online.
Krik had said it's for developers who'd want to quickly test changes on real hardware, so maybe then it's justifiable, but even so, you could still test the bulk of the progress with an emulator, and then move it to the microSD card manually like everyone else.
I actually tried the miniUSB port on my SD2SNES, and it didn't even work... Like, it's supposed to act as a memory stick and another drive should appear in your File Manager. Just like when you plug your camera to your PC with its included USB cable, a drive to the memory card should appear so you can copy/delete files, not have to keep removing the card and inserting it directly into your PC. Well, nothing happened, and I tried it both ways, connected to the system with the power on, and disconnected, etc. I'll have to read up on it more I guess, but out of the box, it didn't even work.