You really do an awesome job here! I really looking forward for the details on the electronics or even the availability of a kit.I really wan't to go and check out some spots around the local lakes here (I'm from Switzerland and go scuba diving here regularly). I'm not really an electronics guy (yet), so can't help there too much.
I'm rather interested in software and could probably help with that. I'm not sure how far you are with the software and if what is in the openrov-software repo on github really is the latest version.
I could probably help you with getting the UI further and help with integrating the on board cam (from the recent blog post I assume that's not working yet).
I just had an idea about some kind of simulator, for example running a small linux install on a virtual machine (VirtualBox for example) utilizing http://www.nongnu.org/simulavr/ or the Arduino Simulator (http://www.arduinodev.com/arduino-simulator/). That could make software development a lot easier.