I was just thinking about this for a bit but couldn't decide if StackExchange would do this. I thought about partnering, but then I thought that it probably wouldn't happen. I don't see an exact reason you would do this but it would be cool if SE offered a partner program or something to communities outside of SE that have become popular. The program could offer stuff like the software for SE sites and a listing in a partner sites tab.
Unfortunately, Stack Exchange no longer provides a subscription service nor can we license the software to create white label sites for 3rd parties. If you can’t find a Stack Exchange site on your subject of expertise, Area 51 is the only way to get a site created. It's a community-driven process where groups of experts come together to build new Q&A sites that work just like Stack Overflow. You can read more about that process here: http://area51.stackexchange.com/faq. Stack Exchange does not engage in any type of partnerships as you described.