Here is why the article doesn't make sense to me: I frequently find that languages in the "dynamic" group (python, ruby, js, smalltalk etc) feel much, much more similar to languages in the "ultra strict" type group (haskell, ocaml, etc), than either do to say, the medium group (c(#|+)*, java). If the case were really that there is some sort of natural order along the type strictness lines, wouldn't it be that python felt closer to c than to haskell in terms of power and expressiveness?
What you're seeing there is the distinction between "manifest typing" [1] and "implicit typing" [2]. With manifest typing, you actually have to tell the compiler the specific type. With implicit, it will figure it out, either because (as discussed in the article) everything is the same type "Object", or because it will do type inference. Most modern type inference has started with Hindley-Milner [3], but move beyond it in various ways with varying degrees of justification and success. Raw HM doesn't seem to be enough to work with in practice, but moving beyond it gets you into the realm of undecidability unpleasantly quickly. But some progress is being made.
The C(/#/++)/Java languages had a lot of people convinced that being statically typed required manifest typing. Including me. I thought I was against static typing, what I was against was manifest typing.
Please don't use "strict" regarding a language's type checking. It's already used in domain theory for functions which rely on arguments being well-defined and computable. It is one of Haskell's defining features that by default, functions and data structures are not strict.
