I've just created a topic in the module development section which may also be a little bit of interest to core development. Or at the very least I hope any response in this thread might give me some insight on how internationalization is handled in the new Drupal 6 core. (Or even better that I might have given a new idea that can be used, but I don't think my post is that shocking at all).
Anyway, this is the topic: http://drupal.org/node/158776
In short I'm saying that I don't like the current way the two existing modules seem to handle translations by simply adding a new node (eg, there is a new node id after creating a translation of a normal page and both original and translated nodes appear in the content section of the administration pages). I also suggest the way I use with my cms.