Yeah, I never use arc's tagging either, because it just isn't useful for anything other than what pg designed it for, namely differentiating between functions and macros.
Hopefully I'll be able to get my hack onto anarki soon so you guys can look at it and tell me if its an improvement at all.
Types are useful in proportion to the number of primitives that can handle them.
That's basically why I built defgeneric; at this point functions len, iso, keep, some, rem, all are all generics, which means they can be extended for new types. (http://github.com/akkartik/arc)
In wart the type system's baked in pretty early on, and I try to use it everywhere I possibly can. (http://github.com/akkartik/wart)
From your description at http://arclanguage.org/item?id=13474, I definitely think it's a step in the right direction. It has already influenced my ideas about how to implement typing in upcoming toy interpreters.
