I have been lurking on the Rails I18n mailing list for a couple of weeks now, and a message was just posted about the Rails I18n website. This promises to be the place where you will find all information regarding the new internationalisation API.
I think the core team is taking an excellent approach towards Rails I18n, even if the current API is a tad too bare-bones for my taste. It’s great to see that Sven is so involved, as this will probably mean that Globalize will come out with excellent I18n support in Rails 2.2.