Daniel,
Regarding a multilingual Squeak I am not sure what to say. On one side I believe that translating menus and dialog boxes are a good thing. Still I have seen many translations that to be keen: are lousy. Happened with some versions of Photoshop (one that I recall) and also did have the same experience with Archicad.
As Diego says, translating entire Smalltalk language doesn't make much sense. Fortunately, The Etoy System can be viewed as a layer on the top of Squeak and the UI can be translatable.
However, current way of translating doesn't give the best result, since the word order in tiles doesn't take the other languages' word order into account.
"Translation is the other side of a tapestry" -- Cervantes
-- Yoshiki