I didn't say Scala represents the last word, I said it's a "successful marriage" of "ML-style functional languages with class-based OO". I implicitly assumed that subtyping is part of of class-based OO.
I expect Scala to gravitate more towards DOT in the future, as early mistakes in Scala's design will be ironed out.
It might be interesting to see how the form of OOP that you are interested in can be expressed in DOT, for example by removing subtyping form D_{<:}. Have a go at it!
I didn't mean to imply you had said it was the last word. The form of OOP that I would be interested in would probably use row polymorphism instead of subtyping. It might indeed be possible to encode this in DOT.
I think understanding the expressivity of the DOT approach vis-a-vis the more conventional 1ML approach should be interesting.
1ML is based on F-omega, which has higher kinds but not dependent sums or products, while D_{<:} has path-dependent products but no apparent higher kinds, if I understand the paper correctly.
I expect Scala to gravitate more towards DOT in the future, as early mistakes in Scala's design will be ironed out.
It might be interesting to see how the form of OOP that you are interested in can be expressed in DOT, for example by removing subtyping form D_{<:}. Have a go at it!