I think htc rhyme dock would need less modification to fit GNex. No need to move the micro usb port, just the top of the dock needs to cut some curves to fit GNex.

Hmm, ok. Coz this was my assumption, htc likes to place their Micro USB slot at left side of the phone, while GNex micro USB is at the bottom. That' why i thought cutting some curves would able to make it suitable dock with least modification required.