Forgot to mention the location. It's in the alpha directory of the alpha site (as usual), but the file is named sword-icu.zip. You will also need the file icudt19.zip, which contains the ICU data DLL that you need to extract to your Sword directory. If you got the latest Diaspora, you don't need this since the data isn't updated. Distributing the DLL separately allows them to be updated separately.
--Chris