For those of you not yet tired of the Moomin obsession: Here is some more.
There are two more moomin books available in English translation; one is The Book About Moomin, Mymble, and Little My, which as near as I can tell is in verse; the other is Who Will Comfort Toffle?, a short book which LiteraryMoose describes as "One of the best love stories I have ever read". Both are in print in the UK. And one more moomin story, previously untranslated, is coming soon! It is the first one Jansson wrote: The Little Trolls and the Great Flood. You can read the translation online here.
Additionally, Jansson wrote a number of non-moomin books. I am reading The Summer Book now; I think it is the only one that has been translated. A nice book -- I'll write more about it later.