It's a great feature that SP is locked up!

I actualy expected the value of Steem to go down becuase it now seems everyone could make easy money.

HF19 will bring the (after conversion to) USD reward down, but the actual reward in Steem-tokens will go up, which is great!
When the price stabelizes, it will regain its value and we are left with more Steem and more USD!