I don't think so. In fact, I'm not even sure it'll be on all the Series 2 watches. I think it may only be available on the Series 2 Nike+ watches. Someone correct me if I'm wrong.
It will be available and work on all versions. It'll be preloaded on the Nike version, but can be used on any Apple Watch. It's already available on the 1st gen, and will be updated shortly to support series 2