The current hardfork determinant whether our rewards are in Steem or SBD is by checking the debt ration of Steem.
With the new hardfork, if the debt ratio is below 9% we will be receiving 100% rewards in SBD (50% in the form of Steem power is constant).
If the debt ratio plays in between 9-10%, then a proportion of Steem/SBD will be given to us (the same thing happened last hardfork where the debt ratio became in between 2-5%). The closer the debt ratio is to 10%, the bigger portion of Steem rewards will be given.
If it exceeds 10%, then we will be receiving all Steem rewards (100% in Steem).
To calculate the Debt ratio :
Debt Ratio = Market cap of SBD/ Market cap of Steem
check steemd.com for more information or steem.supply