This is good news provided that rewarding minnows is not at the expense of simply rewarding quality content regardless of it's source.
Also I'd hope that the ability for whales to earn more by voting on minnows isn't factoring into their decision making, else that will be very short sighted also.
There's certainly a debate to be had here. If a dolphin created a post that was slightly better than a very similar minnow post, will the whale vote for the minnow still? How about if it was substantially better? Do the whales hold a lower bar of quality for minnows than dolphins? I don't have any answers here, but it'd be great if some whales chimed in.