I guess I can see where you are coming from, but there is the whole sun thing... The simple fact that they already have a partener,  who owns an OS arch. means alot. To jump on ReactOS, they would have to be convinced that ReactOS was worth it (that it was an equal, or better than MS WinNT), and that it wouldn't cost them anything (porting wise). I think that such a task is posible, becuase as you said, Google would gladly jump on the chance to take pennies from Microsoft, and ReactOS can make that posible.