I was wondering after the discussion of Googles crazy hiring, If you just had such a number of developers that you then had to find a reason to justify within a year or two, what would you work on? Would your perceived quality of these developers impact what you aimed for, and what would you do to assess their quality?
Maybe the question is a bit broad but if you have a direction you're interested in taking this what-if, please run with it.
I'd talk with all of them and help them build multiple teams, by identifying leaders and we'd try a couple of business models. You don't need that many developers to work only on one thing.
Only down the road, when you have something that resembles more like a product and a proper team that increasing headcount will yield more work done. You need to build and grow the team based on the scope you've got.
It goes without mentioning that you need people from other areas, like sales, to do anything useful.