If there was a USB modchip, that would mean that Nintendo would have to be noob enough to give the USB port permissions to write to F/W or to the DVD drive. They're alot smarter than that. But evidently not smart enough to remove the DVD drive's serial (or debug, i dunno) port. ^^
So: USB modchip is prolly never going to happen. Anyways, I have soft modded my PS2 and I modded my wii with wiikey. I prefer the hard mod. Even though during installation you might be sweating bullets, after that, its pretty smooth sailing. Swap magic is a pain, 'cause you need to wait like 30 seconds while the swapmagic disc spins up, and lets you boot what you want.