The recent Insight Editions press release posted during the launch of Diablo III: Book of Cain formerly stated the launch in Europe would take place on February 7th. However, the date has been moved forward a few weeks from its original goal.
According to various Blizzard European Community Managers Diablo III: Book of Cain will hit Europe in several languages around mid-March (March 15, 2012). These are not english copies. Each publisher will launch a localized version of Diablo III: Book of Cain available in: deutsch, español, UK english, italian, 한국어 (korean), and francais.
You can pre-order Diablo III: Book of Cain in your respective country here:
Diablo : Le livre de Caïn (France)
Diablo III: Cain Chronik (Germany)
Diablo III: Book of Cain (España)
The Spanish and Italian versions aren't listed yet in Amazon, but I'll continue to monitor it and update you accordingly when that happens.