Will Ethereum take over Bitcoins position? Most likely. Ethereum can do what bitcoin does and does it better and Ethereum can do A LOT more. But there are plenty more fish in the sea.
Personally I believe there will be a very interesting battle between Ethereum and Stratis. They don't have the exact same focus but Stratis can do the same as Ethereum and according to the developers it can do it better because of better design choices. Interesting times ahead of us!
I'm glad you mentioned Stratis. Stratis has enormous potential. However, I believe that ether will be too strong
That's why I'm invested in both ;)
Then we have something in common =)