I think a significant part of the Tesla Energy announcement was justification and risk mitigation for the Gigafactory. "See, look!! We have another huge demand for batteries, so even if our cars don't meet projections, we still need this huge factory!".
Yes yes yes yes yes and yes, and also give them more $ to make the packs, and also to get more companies to develop the essential equipment, compatible products and programming for them. Also, they have been installing test packs for a while now, so I think it's more real than us consumers get to experience. They've said they already have customers, but we haven't seen the customer reviews yet. So, still some more time before it becomes widespread.