Other than answering the question "why?", Steve Dekorte's io programming language looks like a lot of fun. A radically simple mixture of Smalltalk, Self, Actor, and Lisp concepts, the cute bits are that the implementation plays really well with C, meaning io is easy to embed in other programs and easy to develop bindings to C libraries for. Out of the box looks like you can get a lot done. OOPSLA paper and slides for more details.
Could be useful as a pedagogical tool. A relatively pure OOP language would be interesting to explore in a PLDI class.