We have been asked about the possibility of translations to other languages. So far we have people interested in helping out or wanting translations in Spanish, French, Japanese, Chinese, Italian, Swedish, Vietnamese, and Korean.
These can not happen until the book is completed and require third party publisher of said version to contract with Manning.
If you are interested in such translations -- please let us know:
Post your interest and answers to the above at our PostGIS in Action Book Translation thread
pgRouting: A Practical Guide is available in Hardcopy from Hardcopy from Amazon. E-Book or Bulk discounts on Hard-copy from Locate Press.