Its interesting stuff, but that article is misleading/out-of-date. Quotes like:

Which brings up another aspect of const in D - it's transitive. Const in C++ is not transitive,

suggests that D's const is superiour to C++ const because it is transitive. But, they more recently had to add an new keyword: invariant to try and achieve that transitivity. The big debate now is how to make those two work together. More interesting stuff, unless you're trying to get some work done.