You can already migrate to the new ethereum solarcoin:
https://medium.com/solarcoin/migrating-to-ethereum-based-solarcoin-the-technical-guide-ad2de4dba152

At block 3932000, they will take a snapshot and populate the new blockchain.
While I'm typing this we are at block 3931412, so I guess within a few days?

At that point, staking on the old (and new) chain stops.