I don't think a successor exists in the hobby yet. Some of todays most known figures have extraordinary vision and ability, some have seemed to master the science of it all and the ability to grow stuff to unprecedented levels. But I don't believe anybody is blowing the doors off the hobby like Amano did. He laid the groundwork for today's geniuses to build from. I'm not saying their won't ever be another Amano, but personally I don't see one right now.
Amano is the Gretzky of our sport. There are many greats out there today, but no Gretzkys
When a successor arrives, we'll know it. It may or may not be in our lifetime though...
92% of all statistics are made up on the spot.