I know of a few that wont be participating, but only because of their personal financial circumstances. Seems like a low risk play to opt-in on the SPP. The biggest risk is being scaled back, which would be frustrating, but it's a likely outcome.
MCR management have been known as fast-movers in the past - I hope they can get their Ni operations up and running quickly as soon as they're economically viable again. With Au and Ni production, it's not unreasonable to predict a share price of $1+ in the near future.
MCR Price at posting:
36.0¢ Sentiment: Buy Disclosure: Held