From Diablo Wiki

Introduction

Bows have been confirmed to return in Diablo III. A Short Bow can be seen dropped in the WWI 2008 gameplay video, and two archers accompanied the Barbarian during the Deckard Cain rescue sequence. It is unknown whether or not any of the 4 confirmed classes can use bows, though it is likely. No bows dropped during the Blizzcon 2009 demo, likely because they were disabled. This may be a small hint towards the fifth, unknown class using bows as a main source of damage.