Like others here I believe such a game should start as a pure subsim, but I also believe it's important to build a system with expandability in mind. That way, when we have a solid product - well beyond proof of concept - we can start thinking about developing air and surface platforms, provided that there's a demand for them.
Having said that, this is a really clever idea. I would love to lend a hand, especially since I have almost too much free time over the summers. I could help out with graphic-type things, like interfaces and promo material (eg websites). I consider myself competent with Photoshop, some of you may recall that I won the
Silent Hunter 4 Magazine Ad competition a few months ago.
I also have experience researching naval topics and am in regular communication with a few former admirals
Edit: Yes Sid, I know the pains of working on such intricate projects with partners. When I was developing a community game not long ago, our policy eventually became that there could be only one coder at a time. We recognized that he had the ultimate architecture for how everything was supposed to work in his head. We found it best for us to avoid stepping on his toes and stick to our respective "peripheral" tasks and consult from time to time to make sure we were still heading towards the same goal.