Great news for international Suehiro Maruo fans, the Spanish edition of "The Strange Tale of Panorama Island" debuted at FICÓMIC (Salón Internacional del Cómic de Barcelona) recently [UPDATED! - Thanks, Manuel!]. The book was published by Maruo's longtime Spanish publisher Glènat.
I don't know any specific details, but I assume Maruo/EnterBrain's long-running relationship with Glènat may be the reason this edition came out so quickly. The book is available now and sells for 15€. Enjoy, Spanish-reading manga fans!
UPDATE: Glenat posted a little something about their Spanish edition on their manga blog.