The question has been asked by several people: how can we run a node and/or be a steward?
First of all, some who ask this question are assuming that they need to stand up a (validator) node to participate in Sovrin. That isn't necessarily true. A node is a great way to learn, but you can interact with the sovrin network without a node of your own.
If you have serious interest in being a steward (an org that donates a high-performance, carefully administered validator node to the global community), then you can experiment now, and you should stay tuned as the Sovrin Foundation begins to elaborate the rules of governance that stewards will have to live by.
But for today, anybody who wants to can stand up a node, and here's how:
(I think the Linux setup is a bit easier, FWIW...)